CN102083870B - Ethylene copolymer and a method of preparing the same - Google Patents

Abstract

Provided are ethylene copolymers and a process for preparing the same. More specifically, provided are ethylene copolymers exhibiting excellent processibility and physical properties due to its multimodal molecular weight distribution index, through a multi-stage process by using reactors connected in series or in parallel in the presence of catalyst composition containing transition metal catalyst, and a process for preparing the same.

Description

Ethylene copolymer and its preparation method

technical field

The present invention relates to ethylene copolymers and a process for their preparation. More particularly, it relates to an ethylene copolymer exhibiting excellent processability and physical properties due to its multimodal molecular weight distribution index, and a method of preparing the same via a multi-step synthesis.

Background technique

Generally, polymers polymerized using single-site catalysts show narrower molecular weight distributions and uniform distributions of comonomers, and higher copolymerization activities than Ziegler-Natta catalysts. However, due to its narrow molecular weight distribution, processing requires high energy consumption, which is difficult to carry out with existing equipment and increases processing costs. When analyzing the technology of polymerizing olefins using single-site catalysts from the standpoint of conventional commercial methods, which can be directly applied if the solubility of the single-site catalysts in the solvent is high enough (in the case of high-pressure solution methods), significant problems It is the stability of the catalyst at higher polymerization temperatures, and the removal of catalytic activity during post-reactor processing steps, as well as the separation of impurities and reaction inhibitors during separation, purification and solvent recovery.

In order to ensure processability and improved physical properties of an ethylene copolymer polymerized using a single-site transition metal catalyst, it is advantageous for the copolymer to have a broad molecular weight distribution, or a molecular weight distribution showing two or more peaks in a molecular weight distribution curve.

In order to produce such ethylene copolymers with improved processability and physical properties, US Patent No. 4,935,474 discloses a method in which two or more metallocene catalysts having different reaction rates are used in one reactor. However, according to this method, although a polymer having a broad molecular weight distribution or a bimodal molecular weight distribution can be produced, it is difficult to produce ethylene copolymers having various density distributions.

U.S. Patent 3,592,880, EP 057420 and 237294 or British Patent 2020672 etc. disclose the slurry-slurry multi-step polymerization method; British Patent 1505017, EP 040992 or U.S. Patent 4,420,592 etc. disclose the gas phase-gas phase multi-step polymerization method; British Patent 1532231, US Patents 4,368,291, 4,309,521 or 4,368,304 etc. disclose slurry-gas phase multi-step processes. Although WO 9212182 states that more than two steps can be used for the gas phase process in the slurry-gas phase process, due to the catalyst properties and the corresponding introduction of hydrogen, only bimodal molecular weight distribution via the two-step process is shown. The examples of this patent propose the production of ethylene copolymers with a limiting density of at least 0.930 g/cm ³ , thus this method limits the manufacture of ethylene copolymer resins for various uses such as films with high impact strength.

WO 1994/17112 proposed the use of metallocenes and Ziegler-Natta catalysts in solution polymerization to prepare ethylene copolymers with a wider molecular weight distribution, but this method only provided a bimodal molecular weight distribution, and by this improved method There are limited improvements to the physical properties of the polymer.

US Patent 6,277,931 also discloses a method for polymerizing ethylene with a bimodal molecular weight distribution using heterogeneous catalysts (metallocene and Ziegler-Natta catalysts) in a solution polymerization process. However, when heterogeneous catalysts are used in the system, interference between heterogeneous catalysts or with co-catalysts may occur, and thus the reaction will be difficult to control. The promoters of Ziegler-Natta catalysts may act as catalyst poisons or reaction inhibitors for single-site catalysts.

WO 2006/048257 proposes a method to obtain ethylene copolymers with broad molecular weight distribution and trimodal molecular weight distribution via 3 reactors. The process is called slurry-gas phase process, where HDPE with high molecular weight is partially synthesized in a prepolymer reactor prior to the slurry process, followed by a slurry gas phase process to provide a three-modal and broad molecular weight distribution ethylene copolymers. However, a high molecular weight fraction having a high density may cause detrimental effects on the impact strength of the film from the perspective of the entire resin.

US Patent No. 6,372,864 proposes the preparation of ethylene copolymers with satisfactory physical properties and processability in two stirred tank reactors using single site catalysts containing phosphinimine ligands. However, according to this method, a large amount of comonomer needs to be used to obtain low density due to the nature of the catalyst, and thus the comonomer may remain in the final polymer product, causing problems in terms of odor and sanitation.

US Patent 6,995,216 proposes the preparation of ethylene copolymers with a broad molecular weight distribution using single site catalysts containing crosslinked indenoindolyl ligands in multiple steps or in multiple reactors. However, this method does not consider complete mixing of reactants in each step, so the polymer synthesized in each step may have defects due to insufficient mixing.

Contents of the invention

technical problem

In order to solve the problems of the conventional technology, the present inventors conducted intensive research and invented a multi-step solution reaction method for preparing ethylene copolymers having narrow molecular weight distribution and uniform density distribution, which method Using suitable single-site catalysts, the characteristics of ethylene copolymers can be controlled through a multi-step synthesis method, thereby improving the physical properties and processability of ethylene copolymers. Therefore, in each of the two or more reactors connected in multiple steps, by different monomers, comonomer components, reaction temperature or reaction pressure, etc. of polymers.

In particular, according to the above-mentioned multi-step solution reaction method, using alpha-olefin comonomers having at least 3 carbon atoms, it is possible to prepare in each reactor a compound having a different density distribution and having a multimodal molecular weight distribution (preferably having at least bimodal or more peak molecular weight distribution) of ethylene copolymers. The present invention has been accomplished based on this finding. In particular, copolymers with high molecular weights can be prepared using the single-site catalysts of the present invention despite the high degree of comonomer coupling.

Therefore, as a solution to these problems, an object of the present invention is to provide an ethylene copolymer having a multimodal molecular weight distribution and improved physical properties and processability prepared via a multi-step synthesis of ethylene or α-olefin, and the preparation thereof method.

Another object of the present invention is to overcome the disadvantages caused by the mixing preparation, and to provide an ethylene copolymer which is easy to prepare and applicable to various uses, and a preparation method thereof.

Technical solutions

In order to achieve the object of the present invention, one aspect of the present invention provides a method for preparing an ethylene copolymer, the method comprising (a) in one or more reactors, containing a transition metal catalyst represented by chemical formula (1) polymerizing ethylene and one or more C3-C18 alpha-olefin comonomers in the presence of a catalyst composition, thereby producing a first copolymer; and (b) in the presence of the same catalyst composition as used in step (a) At a temperature higher than the reaction temperature of step (a), the first copolymer prepared by step (a) is passed through at least one other reactor containing ethylene or ethylene and at least one C3-C18 α-olefin, thereby producing High temperature polymer of ethylene and C3-C18 alpha-olefin copolymer components.

Another aspect of the present invention provides a process for preparing an ethylene copolymer comprising (a) in one or more reactors, in the presence of a catalyst composition comprising a transition metal catalyst represented by formula (1), polymerizing ethylene and one or more C3-C18 alpha-olefin comonomers to produce a first copolymer; (b) in at least one other reactor, in the same catalyst composition as used in step (a) In the presence of, at a temperature higher than the reaction temperature of step (a), ethylene or ethylene and one or more C3-C18 α-olefins are reacted to prepare a second copolymer; (c) the first copolymer and the second Copolymer blend.

[chemical formula 1]

In this formula, M represents the transition metal of Group 4 of the periodic table of elements;

Cp represents η ⁵ - a cyclopentadiene ring or a fused ring containing a cyclopentadiene ring connected to the core metal M, wherein the cyclopentadiene ring or a condensed ring containing a cyclopentadiene ring can be further substituted optionally One or more substituents selected from (C1-C20) alkyl, (C6-C30) aryl, (C2-C20) alkenyl and (C6-C30) aryl (C1-C20) alkyl;

R ¹ ~ R ⁴ independently represent a hydrogen atom, a halogen atom, (C1-C20) alkyl, (C3-C20) cycloalkyl, (C6-C30) aryl, (C6-C30) aryl (C1-C10) Alkyl, (C1-C20)alkoxy, (C3-C20)alkylsilyloxy, (C6-C30)arylsilyloxy, (C1-C20)alkylamino, (C6-C30) Arylamino, (C1-C20) alkylthio, (C6-C30) arylthio or nitro, or each of R ¹ to R ⁴ can be via (C3-C12) with or without fused ring An alkylene group or (C3-C12) alkenylene group is connected to an adjacent substituent to form an aliphatic ring, or a monocyclic or polycyclic aromatic ring;

Ar ¹ represents (C6-C30) aryl or (C3-C30) heteroaryl containing one or more heteroatoms selected from N, O and S;

X ¹ and X ² independently represent a halogen atom, (C1-C20) alkyl, (C3-C20) cycloalkyl, (C6-C30) aryl (C1-C20) alkyl, (C1-C20) alkoxy radical, (C3-C20) alkylsilyloxy, (C6-C30) arylsilyloxy, (C1-C20) alkylamino, (C6-C30) arylamino, (C1-C20) alkane Sulfuryl, (C6-C30) arylthio or

R ¹¹ to R ¹⁵ independently represent hydrogen atom, halogen atom, (C1-C20) alkyl group, (C3-C20) cycloalkyl group, (C6-C30) aryl group, (C6-C30) aryl group (C1-C10) Alkyl, (C1-C20)alkoxy, (C3-C20)alkylsilyloxy, (C6-C30)arylsilyloxy, (C1-C20)alkylamino, (C6-C30) Arylamino, (C1-C20) alkylthio, (C6-C30) arylthio or nitro, or R ¹¹ to R ¹⁵ can be through (C3-C12) alkylene with or without fused ring Or a (C3-C12)alkenylene group is connected to an adjacent substituent to form an aliphatic ring, or a monocyclic or polycyclic aromatic ring; and

The alkyl, aryl, cycloalkyl, aralkyl, alkoxy, alkylsilyloxy, arylsilyloxy groups of R ¹ to R ⁴ , R ¹¹ to R ¹⁵ , X ¹ and X ² group, alkylamino group, arylamino group, alkylthio group or arylthio group; each of R ¹ to R ⁴ or R ¹¹ to R ¹⁵ is connected to an adjacent substituent via an alkylene or alkenylene group ring; or the aryl or heteroaryl of Ar ¹ can be further substituted with a halogen atom, (C1-C20) alkyl, (C3-C20) cycloalkyl, (C6-C30) aryl, (C6-C30 ) aryl (C1-C10) alkyl, (C1-C20) alkoxy, (C3-C20) alkyl silyloxy, (C6-C30) aryl silyloxy, (C1-C20) alkane One or more substituents of ylamino, (C6-C30)arylamino, (C1-C20)alkylthio, (C6-C30)arylthio, nitro and hydroxyl.

Now, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings. It should be noted that the same components or components are marked with the same symbols in the drawings. In the description of the present invention, specific descriptions of related known functions or structures are omitted to avoid ambiguity.

Terms such as "about" or "substantially" are used herein to refer to a degree (or amount) to denote the value or an approximation when inherent tolerances are made for the formulation or substance; and the term may be used to avoid inappropriate use of the present disclosure Unreasonable infringers of content (in order to facilitate the understanding of the present invention, exact or absolute values are stated in this disclosure).

The ethylene copolymers of the present invention can be prepared in at least two steps and have a narrow molecular weight distribution. This preparation requires a single-site catalytic system that can provide high bonding strength between comonomers with a narrow density distribution. The catalyst used may be a Group 4 transition metal catalyst which is not crosslinked with a ligand and contains a cyclopentadiene derivative and at least one aryl oxide ligand having an aryl derivative substituent in the ortho position, or A catalyst composition comprising the transition metal catalyst and an aluminoxane cocatalyst or a boron compound cocatalyst.

Furthermore, employing a step in the process that provides at least a bimodal molecular weight distribution overcomes the low processability due to the narrow molecular weight distribution of polymers polymerized using single site catalysts. A solution polymerization process can be carried out in which high molecular weight alpha-olefins preferably having at least 3 carbon atoms, more preferably at least 6 carbon atoms, can be used as comonomers.

Therefore, since the density of the high molecular weight part is lower than that of other molecular weight parts, the frequency of existence of tie molecules (tiemolecules) in the molecular chain increases, thereby increasing the impact strength in the case of being used for a film, and the high temperature in the case of being used as a pipe. Improved long-term durability.

The present invention will be described in detail below.

1. Description of the catalyst used

The catalyst used in the present invention is a catalyst composition containing a transition metal catalyst represented by chemical formula (1) and a cocatalyst. The cocatalyst may be selected from boron compounds or aluminum compounds, or mixtures thereof.

First, the compound represented by the chemical formula (1) is a Group 4 transition metal catalyst containing a cyclopentadiene derivative and at least one aryl oxide ligand around the transition metal, and the aryl oxide ligand is at the ortho position There is an aryl derivative substituent, and there is no connection between the ligands.

[chemical formula 1]

In the transition metal catalyst of the chemical formula (1), the core metal M represents a transition metal of Group 4 of the periodic table, preferably titanium, zirconium or hafnium. In this formula, Cp represents η ⁵ - a cyclopentadiene ring or a fused ring containing a cyclopentadiene ring connected to the core metal M, wherein the cyclopentadiene ring or a condensed ring containing a cyclopentadiene ring can be Further substituted with one or more substituents selected from (C1-C20)alkyl, (C6-C30)aryl, (C2-C20)alkenyl and (C6-C30)aryl(C1-C20)alkyl . Specific examples of Cp include cyclopentadienyl, methylcyclopentadienyl, dimethylcyclopentadienyl, tetramethylcyclopentadienyl, pentamethylcyclopentadienyl, butylcyclopentadiene base, sec-butylcyclopentadienyl, tert-butylmethylcyclopentadienyl, trimethylsilylcyclopentadienyl, indenyl, methylindenyl, dimethylindenyl, ethylindenyl, iso Propyl indenyl, fluorenyl, methyl fluorenyl, dimethyl fluorenyl, ethyl fluorenyl, isopropyl fluorenyl and the like.

The groups R ¹ to R ⁴ on the arylphenoxide ligand in chemical formula (1) can independently represent a hydrogen atom, a halogen atom, (C1-C20) alkyl, (C3-C20) cycloalkyl, (C6- C30) aryl, (C6-C30) aryl (C1-C10) alkyl, (C1-C20) alkoxy, (C3-C20) alkyl silyloxy, (C6-C30) aryl silyl Oxygen, (C1-C20) alkylamino, (C6-C30) arylamino, (C1-C20) alkylthio or nitro, or each of R ¹ to R ⁴ may contain or not contain condensed The (C3-C12) alkylene or (C3-C12) alkenylene of the ring is connected to form an aliphatic ring, or a monocyclic or polycyclic aromatic ring;

Ar ¹ represents (C6-C30) aryl or (C3-C30) heteroaryl containing one or more heteroatoms selected from N, O and S;

X ¹ and X ² independently represent halogen, (C1-C20) alkyl, (C3-C20) cycloalkyl, (C6-C30) aryl (C1-C20) alkyl, (C1-C20) alkoxy, (C3-C20)Alkylsilyloxy, (C6-C30)Arylsilyloxy, (C1-C20)Alkylamino, (C6-C30)Arylamino, (C1-C20)Alkylthio Base, (C6-C30) arylthio or

R ¹¹ to R ¹⁵ independently represent a hydrogen atom, a halogen atom, (C1-C20) alkyl, (C3-C20) cycloalkyl, (C6-C30) aryl, (C6-C30) aryl (C1-C10 ) alkyl, (C1-C20) alkoxy, (C3-C20) alkyl silyloxy, (C6-C30) aryl silyloxy, (C1-C20) alkyl amino, (C6-C30 ) arylamino, (C1-C20) alkylthio, (C6-C30) arylthio or nitro, or each of R ¹¹ to R ¹⁵ can be via (C3-C12 ) alkylene or (C3-C12) alkenylene is linked to adjacent substituents to form an aliphatic ring, or a monocyclic or polycyclic aromatic ring; and

The alkyl group, aryl group, cycloalkyl group, aralkyl group, alkoxy group, alkylsilyloxy group, alkylamino group, aryl group of R ¹ to R ⁴ , R ¹¹ to R ¹⁵ , X ¹ and X ² An amino group, an alkylthio group or an arylthio group; a ring formed by connecting each of R ¹ to R ⁴ or R ¹¹ to R ¹⁵ with an adjacent substituent via an alkylene or alkenylene group; or the aromatic group of Ar ¹ The radical or heteroaryl can be further substituted with a halogen atom, (C1-C20) alkyl, (C3-C20) cycloalkyl, (C6-C30) aryl, (C6-C30) aryl (C1-C10 ) alkyl, (C1-C20) alkoxy, (C3-C20) alkyl silyloxy, (C6-C30) aryl silyloxy, (C1-C20) alkyl amino, (C6-C30 One or more substituents of ) arylamino, (C1-C20) alkylthio, (C6-C30) arylthio, nitro and hydroxyl.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. Examples of (C1-C20)alkyl or (C3-C20)cycloalkyl include methyl, ethyl, n-propyl, i-propyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, neo Pentyl, n-hexyl, n-octyl, n-decyl, n-dodecyl, n-pentadecyl and n-eicosyl, among which methyl, ethyl, isopropyl or tert-butyl are preferred; (C6 Examples of -C30)aryl include phenyl, naphthyl, anthracenyl and fluorenyl; examples of (C6-C30)aryl(C1-C20)alkyl include benzyl, (2-methylphenyl)methyl , (3-methylphenyl)methyl, (4-methylphenyl)methyl, (2,3-dimethylphenyl)methyl, (2,4-dimethylphenyl)methyl , (2,5-dimethylphenyl) methyl, (2,6-dimethylphenyl) methyl, (3,4-dimethylphenyl) methyl, (4,6-dimethyl phenyl)methyl, (2,3,4-trimethylphenyl)methyl, (2,3,5-trimethylphenyl)methyl, (2,3,6-trimethylphenyl) base) methyl, (3,4,5-trimethylphenyl)methyl, (2,4,6-trimethylphenyl)methyl, (2,3,4,5-tetramethylphenyl base) methyl, (2,3,4,6)-tetramethylphenyl) methyl, (2,3,5,6-tetramethylphenyl) methyl, (pentamethylphenyl) methyl Base, (ethylphenyl)methyl, (n-propylphenyl)methyl, (isopropylphenyl)methyl, (n-butylphenyl)methyl, (sec-butylphenyl)methyl , (n-tetradecylphenyl)methyl, triphenylmethyl, naphthylmethyl and anthracenylmethyl, among which benzyl or triphenylmethyl is preferred; examples of (C1-C20)alkoxy Including methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, tert-butoxy, n-pentoxy, neopentyloxy, n-hexyloxy, n-octyl Oxy, n-dodecyloxy, n-pentadecyloxy and n-eicosyloxy, of which methoxy, ethoxy, isopropoxy or tert-butoxy are preferred; (C3-C20)alkane Examples of ylsiloxy or (C6-C30)arylsiloxy include trimethylsiloxy, triethylsiloxy, tri-n-propylsiloxy, triisopropylmethylsiloxy, Siloxyl, tri-n-butylsilyloxy, tri-sec-butylsilyloxy, tri-tert-butylsilyloxy, triisobutylsilyloxy, tert-butyldimethylsilyloxy, tri-n-pentylsilyloxy group, tri-n-hexylsilyloxy group, tricyclohexylsilyloxy group, phenylsilyloxy group, diphenylsilyloxy group and naphthylsilyloxy group, among which trimethylsilyloxy group, tert-butyldimethylsilyloxy or phenylsilyloxy.

Examples of (C1-C20) alkylamino or (C6-C30) arylamino include dimethylamino, diethylamino, di-n-propylamino, diisopropylamino, di-n-butylamino, di-sec Butylamino, di-tert-butylamino, diisobutylamino, tert-butylisopropylamino, di-n-hexylamino, di-n-octylamino, di-n-decylamino, diphenylamino, dibenzylamino, methyl methylethylamino, methylphenylamino and benzylhexylamino, among which dimethylamino, diethylamino or diphenylamino are preferred; (C1-C20) alkylthio or (C6-C30) aryl Examples of the thio group include methylthio, ethylthio, isopropylthio, phenylthio and naphthylthio.

A specific example of the compound of formula (1) can be represented by one of the following formulas:

[chemical formula 1-1]

[chemical formula 1-2]

[chemical formula 1-3]

[chemical formula 1-4]

[chemical formula 1-5]

[chemical formula 1-6]

[chemical formula 1-7]

[chemical formula 1-8]

[chemical formula 1-9]

[chemical formula 1-10]

[chemical formula 1-11]

[chemical formula 1-12]

[chemical formula 1-13]

[chemical formula 1-14]

In the formula, R ²¹ to R ²⁶ independently represent hydrogen atom, halogen atom, (C1-C20) alkyl group, (C3-C20) cycloalkyl group, (C6-C30) aryl group, (C6-C30) aryl group (C1 -C10)alkyl, (C1-C20)alkoxy, (C3-C20)alkylsilyloxy, (C6-C30)arylsilyloxy, (C1-C20)alkylamino, (C6 -C30) arylamino, (C1-C20) alkylthio, (C6-C30) arylthio or nitro, or each of R ²¹ to R ²⁶ can be selected via ( C3-C12) alkylene or (C3-C12) alkenylene is connected with adjacent substituents to form aliphatic ring, or monocyclic or polycyclic aromatic ring; R ²¹ ~ R ²⁶ alkyl, aryl, ring The alkyl, aralkyl, alkoxy, alkylsiloxy, arylsiloxy, alkylamino, arylamino, alkylthio or arylthio groups may be further substituted with halogen atoms selected from , (C1-C20) alkyl, (C3-C20) cycloalkyl, (C6-C30) aryl, (C6-C30) aryl (C1-C10) alkyl, (C1-C20) alkoxy, (C3-C20)Alkylsilyloxy, (C6-C30)Arylsilyloxy, (C1-C20)Alkylamino, (C6-C30)Arylamino, (C1-C20)Alkylthio One or more substituents of radical, (C6-C30)arylthio, nitro and hydroxyl;

Cp represents η ⁵ - a cyclopentadiene ring or a fused ring containing a cyclopentadiene ring connected to the core metal M, wherein the cyclopentadiene ring or a condensed ring containing a cyclopentadiene ring can be further substituted optionally One or more substituents selected from (C1-C20)alkyl, (C6-C30)aryl, (C2-C20)alkenyl and (C6-C30)aryl(C1-C20)alkyl; and

X ¹ and X ² represent methyl or Cl.

More specifically, the present invention provides a process for the preparation of ethylene copolymers characterized by a transition metal catalyst selected from the group consisting of:

In the formula, Cp represents η ⁵ - a cyclopentadiene ring or a condensed ring containing a cyclopentadiene ring connected to the core metal M, wherein the condensed ring containing a cyclopentadiene ring can be further substituted with a group selected from (C1 One or more substituents of -C20)alkyl, (C6-C30)aryl, (C2-C20)alkenyl and (C6-C30)aryl(C1-C20)alkyl; and

X ¹ and X ² represent methyl or Cl.

In order for the transition metal catalyst of formula (1) to be an active catalyst component for the polymerization of olefins, an aluminum compound or a boron compound or a mixture thereof, which can be obtained from a transition metal compound, is used as a cocatalyst The X ligand is extracted, thereby making the core metal a cation and at the same time serving as a counterion (anion) with weak bonding strength. Although the organoaluminum compound used here is to remove traces of polar species which function as catalyst poisons in the reaction solvent, it can act as an alkylating agent when the X ligand is a halogen.

Boron compounds useful as cocatalysts in the present invention may be selected from compounds represented by any of formulas (2) to (4) (as seen in US Pat. No. 5,198,401).

[chemical formula 2]

B(R ³¹ ) ₃

[chemical formula 3]

[R ³² ] ⁺ [B(R ³¹ ) ₄ ] ^-

[chemical formula 4]

[(R ³³ ) _q ZH] ⁺ [B(R ³¹ ) ₄ ] ^-

In chemical formulas (2)-(4), B represents a boron atom; R ³¹ represents a phenyl group, which can be further substituted with a (C1-C20) alkane selected from a fluorine atom, with or without a fluorine substituent or 3 to 5 substituents of (C1-C20) alkoxy groups with or without fluorine substituents; R ³² represents (C5-C7) cycloalkyl, (C1-C20) alkyl (C6- C20) aryl or (C6-C30) aryl (C1-C20) alkyl such as triphenylmethyl; Z represents a nitrogen atom or a phosphorus atom; R ³³ represents a nitrogen atom substituted with 2 (C1-C4) alkane and q is an integer 2 or 3.

Preferred examples of boron-containing cocatalysts include tris(pentafluorophenyl)borane, tris(2,3,5,6-tetrafluorophenyl)borane, tris(2,3,4,5-tetrafluorobenzene base)borane, tris(3,4,5-trifluorophenyl)borane, tris(2,3,4-trifluorophenyl)borane, phenylbis(pentafluorophenyl)borane, tetrafluorophenyl (Pentafluorophenyl) borate (or ester), tetrakis (2,3,5,6-tetrafluorophenyl) borate (or ester), tetrakis (2,3,4,5-tetrafluorobenzene Base) borate (or ester), tetrakis (3,4,5-trifluorophenyl) borate (or ester), tetrakis (2,2,4-trifluorophenyl) borate (or ester) ), phenyl bis(pentafluorophenyl) borate (or ester) and tetrakis[3,5-bis(trifluoromethyl)phenyl] borate (or ester). Its specific complex (blend) includes tetrakis (pentafluorophenyl) borate ferrocene, tetrakis (pentafluorophenyl) borate 1,1'-dimethylferrocene, tetrakis (pentafluorophenyl) silver borate, Triphenylmethyltetrakis(pentafluorophenyl) borate, triphenylmethyltetrakis[3,5-bis(trifluoromethyl)phenyl]borate, triphenylmethyltetrakis(pentafluoro Phenyl) borate, triethylammonium tetrakis (pentafluorophenyl) borate, tripropylammonium tetrakis (pentafluorophenyl) borate, tri-n-butylammonium tetrakis (pentafluorophenyl) borate, tetrakis [3 , 5-bis(trifluoromethyl)phenyl] tri-n-butylammonium borate, tetrakis(pentafluorophenyl) borate N,N-dimethylanilinium, tetrakis(pentafluorophenyl) borate N,N- Diethylanilinium, N,N-2,4,6-pentamethylanilinium tetrakis(pentafluorophenyl)boronic acid, N,N tetrakis[3,5-bis(trifluoromethyl)phenyl]boronic acid -Dimethylanilinium, diisopropylammonium tetrakis(pentafluorophenyl)borate, dicyclohexylammonium tetrakis(pentafluorophenyl)borate, triphenylphosphonium tetrakis(pentafluorophenyl)borate, tetrakis(pentafluorophenyl)borate Tris(methylphenyl)phosphonium fluorophenyl)borate and tris(dimethylphenyl)phosphonium tetrakis(pentafluorophenyl)borate. Among them, N,N-dimethylanilinium tetrakis (pentafluorophenyl) borate, triphenylmethyl tetrakis (pentafluorophenyl) borate and tris (pentafluorophenyl) borane are more preferable. The molar ratio of core metal M:boron atoms is preferably 1:0.1-50, more preferably 1:0.5-15.

Aluminum compounds usable in the present invention include aluminoxane compounds represented by chemical formula (5) or (6), organoaluminum compounds represented by chemical formula (7), and organoaluminum alkoxides represented by chemical formula (8) or (9).

[chemical formula 5]

(-Al(R ⁴¹ )-O-) _m

[chemical formula 6]

(R ⁴¹ ) ₂ Al-(-O(R ⁴¹ )-) _p -(R ⁴¹ ) ₂

[chemical formula 7]

(R ⁴² ) _r Al(E) _3-r

[chemical formula 8]

(R ⁴³ ) ₂ AlOR ⁴⁴

[chemical formula 9]

R ⁴³ Al(OR ⁴⁴ ) ₂

In chemical formulas (5) to (9), R ⁴¹ represents a linear or non-linear (C1-C20) alkyl group, preferably methyl or isobutyl; m and p each represent an integer of 5 to 20; R ⁴² and R ⁴³ represent (C1-C20)alkyl; E represents a hydrogen atom or a halogen atom; r is an integer of 1 to 3; and R ⁴⁴ may be selected from (C1-C20)alkyl and (C6-C30)aryl.

Specific examples of aluminum compounds that can be used include aluminoxane compounds such as methylalumoxane, modified methylalumoxane, and tetraisobutylalumoxane; organoaluminum compounds including trialkylaluminum compounds such as trimethylalumoxane aluminum triethyl, triethylaluminum, tripropylaluminum, triisobutylaluminum and trihexylaluminum; dialkylaluminum chlorides such as dimethylaluminum chloride, diethylaluminum chloride, dipropylaluminum chloride Aluminum, diisobutylaluminum chloride, and dihexylaluminum chloride; alkylaluminum dichlorides such as methylaluminum dichloride, ethylaluminum dichloride, propylaluminum dichloride, isobutylaluminum dichloride aluminum chloride and hexylaluminum dichloride; and dialkylaluminum hydrides such as dimethylaluminum hydride, diethylaluminum hydride, dipropylaluminum hydride, diisobutylaluminum hydride and dihexylaluminum hydride. Among them, trialkylaluminum is preferable, and triethylaluminum or triisobutylaluminum is more preferable. The molar ratio of core metal M:aluminum atoms is preferably 1:1 to 1:2000, more preferably 1:5 to 1:1,000.

The molar ratio of core metal M: boron atom: aluminum atom is preferably 1:0.1-50:1-1,000, more preferably 1:0.5-15:5-500.

2. Solution polymerization method

Since the ethylene polymerization of the present invention is carried out in at least two steps, two or more reactors are required. 2 or 3 polymerization steps are performed to obtain a broad molecular weight distribution.

The method for preparing ethylene copolymer of the present invention is carried out at a reaction temperature of 80°C to 210°C (step (a)) and 90°C to 220°C (step (b)) under a pressure of 20atm to 500atm.

In step (a), in the presence of the catalyst or catalyst composition, the polymerization is carried out at a temperature of 80°C to 210°C, more preferably 80°C to 150°C, and a pressure of 20atm to 500atm, more preferably 30atm to 200atm. If the reaction temperature is lower than 80° C., the reaction cannot occur due to precipitation or insufficient dispersion of the reactants, thus making it difficult to form a polymer. If the reaction temperature exceeds 210°C, a polymer having a predetermined molecular weight cannot be produced. If the pressure is not within the above range, it is difficult to obtain a polymer having a desired molecular weight.

Then, in step (b), in the presence of the same catalyst or catalyst composition used in step (a), at a temperature of 90°C to 220°C, more preferably 120°C to 200°C, and with step (a) Under the same pressure, the polymer prepared in step (a) is copolymerized with α-olefin. If the temperature is lower than 90°C, the polymer may precipitate, or produce the same polymer as that obtained in step (a), thereby eliminating the effect of multi-stage polymerization. If the temperature exceeds 220°C, the molecular weight of the polymer becomes too low, impairing its physical properties. For pressure, the same corresponding results as in step (a) can be obtained.

At the same time, the present invention is dedicated to controlling the physical properties and conversion rate of ethylene copolymers with uniform molecular weight and multimodal density distribution through different process conditions such as the amount of ethylene or hydrogen introduced in step (a) or (b). In particular, the present invention aims to optimize the tether molecules in the molecular structure through the predetermined ratio of high molecular weight and low density polymer in step (a), thereby improving the physical properties of the final resin, such as tensile strength and impact strength. In step (b) following step (a), the same catalyst or catalyst composition is used, but the polymerization is carried out at a higher temperature, thereby providing a polymer having a different molecular weight and density than that prepared in step (a) range of ethylene copolymers. Due to the characteristics of the transition metal catalysts of the present invention, the resulting polymers exhibit narrower molecular weight distributions and density distributions. However, by controlling the entire multi-step reaction, it is also possible to obtain the broad molecular weight and density distribution desired by the manufacturer.

During the whole multi-step reaction process, the arrangement of reactors can be in series or in parallel.

Figure 1 is a schematic diagram of reactors arranged in series in a preferred embodiment of the present invention. Referring to Fig. 1, the series reactor comprises the feed heater (13) of stage-1 feed pump (11), stage-1 feed cooler (12), stage-1 reactor, stage-1 low temperature reactor ( 14), the catalyst feeding part (15) of stage-1 low temperature reactor, the catalyst feeding part (17) of stage-2 high temperature reactor (16), stage-2 high temperature reactor in series, the stage-2 reactor Feed pump (18), feed cooler (19) for stage-2 reactor, feed heater (20) for stage-2 reactor, feed piece (21) and hydrogen feed for stage-2 reactor Material (22).

Therefore, the series reaction of the present invention includes: the reactant except catalyst is supplied to the stage-1 low temperature reactor (14) by the feed pump (11) of the stage-1 reactor, and the stage-1 low temperature reactor ( 14) Equipped with a temperature controller and including a feed cooler (12) for a stage-1 reactor and a feed heater (13) for a stage-1 reactor; a catalyst feed through a stage-1 low temperature reactor (15) Catalyst supplied; and step (a) carried out at a temperature lower than stage-2. The polymer obtained via step (a) is directly fed to the stage-2 high temperature reactor (16) in series, which is equipped with the feed cooler (19) of the stage-2 reactor and the stage Feed Heater (20) of -2 Reactor; Catalyst is supplied by Catalyst Feed (17) of Stage-2 High Temperature Reactor; Reactants are supplied to Stage by Feed Pump (18) of Stage-2 Reactor - 2 reactor feeds (21) with hydrogen supplied via a hydrogen feed (22); and the polymerization of step (b) is carried out at a higher temperature than that of step (a). For reactors in series, the whole reactor system needs to be designed and controlled considering the ethylene conversion and the catalytic activity of the stage-1 reaction.

Figure 2 is a schematic diagram of reactors arranged in parallel in a preferred embodiment of the present invention. With reference to Fig. 2, parallel reactor comprises the feed pump (31) of low temperature reactor, the feed pump (32) of high temperature reactor, the feed cooler (33) of low temperature reactor, the feed heater of low temperature reactor (34), the feed cooler (35) of the high temperature reactor, the feed heater (36) of the high temperature reactor, the low temperature reactor (37), the catalyst feed part (38) of the low temperature reactor, the high temperature reactor Catalyst feed (39), high temperature reactor (40), inline mixer (in-line mixer) (41), high temperature reactor feed (42) and hydrogen feed (43).

Thus, the reactants (except catalyst) are fed to the low temperature reactor (37) by the feed pump (31) of the low temperature reactor (which is heated by the feed cooler (33) of the low temperature reactor and the feed to the low temperature reactor device (34) to control the temperature); and add catalyst through the catalyst feed member (38) of the low temperature reactor, thereby carrying out the step (a) of the reaction in the parallel reactor.

Different from step (a), the reactants (except catalyst) are supplied to the high temperature reaction via the feed pump (32) of the high temperature reactor, and then via the feed piece (42) and the hydrogen feed piece (43) of the high temperature reactor device (40) (wherein the temperature is controlled by the feed cooler (35) of the high temperature reactor and the feed heater (36) of the high temperature reactor); and the catalyst feed (39) of the high temperature reactor is added to the catalyst, The reaction is thereby carried out at a temperature higher than that of step (a). The low-temperature reactant and the high-temperature reactant are mixed in an inline mixer (41) to obtain a homogeneous copolymer.

For this reaction in parallel reactors, the solutions from each reactor were homogeneously mixed using an in-line mixer, thereby providing uniform physical properties of the copolymer. In order to obtain homogeneous copolymers, any possible unit such as stirred tanks and inline mixers can be used.

In steps (a) and (b) of the present invention, the preferred amounts of ethylene and one or more C3-C18 α-olefin comonomers are 60% to 99% by weight of ethylene and 1% to 40% by weight, respectively % alpha-olefin comonomer. When the ethylene content is less than 60%, desired properties of ethylene cannot be developed due to the low ethylene content, thereby deteriorating physical properties. If the ethylene content is higher than 99% by weight, the effect of the copolymer will be reduced.

In steps (a) and (b), specific examples of C3-C18 α-olefin comonomers include propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene and mixtures thereof. Of these, 1-butene, 1-hexene, 1-octene or 1-decene are more preferred.

Preferred organic solvents for polymerization in steps (a) and (b) are C30-C20 hydrocarbons. Specific examples of the solvent include butane, isobutene, pentane, hexane, heptane, octane, isooctane, nonane, decane, dodecane, cyclohexane, methylcyclohexane, benzene, toluene and Xylene, etc. Examples of commercially available solvents suitable for this process are solvents of the SK-ISOL series, an isoparaffinic solvent. For example, SK-ISOL E (available from SK Energy) is a C8-C12 aliphatic hydrocarbon solvent with a distillation range of 117°C-137°C.

The ethylene copolymer prepared according to the method of the present invention is characterized in that it contains 10% to 70% by weight of the polymer prepared in step (a) and 30% to 90% by weight of the polymer prepared in step (b); And the polymer of step (a) has an MI of 0.001 g/10 min to 2.0 g/10 min and a density of 0.860 g/cm ³ to 0.925 g/cm ³ , and the polymer of step (b) has a density of 0.1 g/cm 3 An ethylene copolymer with an MI of 10 minutes to 100.0 g/10 minutes and a density of 0.900 g/cm ³ to 0.970 g/cm ³ .

Firstly, the content of the polymer prepared in step (a) is 10% to 70% by weight, preferably 20% to 60% by weight. If the content of the step (a) polymer is less than 10% by weight, no improvement in impact strength occurs. If the content exceeds 70% by weight, transparency significantly deteriorates when processed into a film, and thus high energy is required for processing, and productivity is low.

Based on the MI (melt index) measurement carried out according to ASTM D2839, the molecular weight of the polymer prepared in step (a) is 0.001 g/10 minutes to 2.0 g/10 minutes, more preferably 0.005 g/10 minutes to 1.0 g/10 Minutes from MI. If the MI of the polymer produced in the step (a) is less than 0.001 g/10 minutes, the produced polymer is too hard resulting in poor processability. If the MI is greater than 2.0 g/10 minutes, the overall physical properties of the polymer, such as tensile strength and impact strength, do not appear to be significantly improved. According to the report of Tetsuya, Yoshigio, Takagi Hatori et al. ('High Performance PE 100 Resin with Extraordinary Resistance of Slow Crack Growth', Plastics Pipes XIII Conference, 2007), in the multi-step process for preparing ethylene copolymers with multimodal molecular weight distribution, It is advantageous to preferentially polymerize the higher molecular weight moiety in order to obtain a better dispersion of this moiety throughout the resin.

The polymer produced in step (a) has a density of 0.860g/cm ³ to 0.925g/cm ³ , more preferably 0.880g/cm ³ to 0.915g/cm ³ . If the density is lower than 0.860 g/cm ³ , the prepared film will have poor physical properties. If the density exceeds 0.925 cm ³ , the film will be too stiff. The polymer produced in step (a) will be a resin with a lower density range. A resin in which the copolymerized comonomer is uniformly distributed in the polymer chain is synthesized by a single-site transition metal catalyst that is different from the one that provides the polymer Ziegler-Natta catalysts with heterogeneous copolymer distribution in the chain.

On the other hand, the content of the polymer prepared in step (b) is 30% to 90% by weight, more preferably 40% to 80% by weight. If the content of the polymer of step (b) is less than 30% by weight, the processability of the final resin (due to the high molecular weight, low density ethylene copolymer prepared in step (a)) and the transparency of the film will be poor. If the content exceeds 90% by weight, the content of the polymer prepared in step (a), which provides good physical properties, becomes low, resulting in a resin with lower environmental resistance, impact strength, tensile strength.

Based on the MI (melt index) measurement carried out according to ASTM D2839, the molecular weight of the polymer prepared in step (b) is 0.1 g/10 minutes to 100.0 g/10 minutes, more preferably 0.3 g/10 minutes to 50.0 g/10 Minutes from MI. If the MI of the polymer prepared in step (b) is less than 0.1 g/10 min, the molecular weight range overlaps with that of the polymer prepared in step (a), so that the molecular weight distribution is not broad enough to realize the advantages of multi-step reaction. If the MI exceeds 100 g/10 minutes, physical properties will be deteriorated due to low molecular weight.

The polymer produced in step (b) preferably has a density of 0.900g/cm ³ to 0.970g/cm ³ . If the density is lower than 0.900 g/cm ³ , this density is covered by the density range of the polymer produced in step (a), so that the effect of staged polymerization is lost. If the density exceeds 0.970 cm ³ , problems arise because the film produced therefrom is too hard. Therefore, the density range of the polymer prepared in step (a) and the density range of the polymer prepared in step (b) should be adjusted to optimize the physical properties of the resin.

The ethylene copolymer prepared according to the method of the present invention comprises a linear low density polyethylene copolymer (LLDPE) having a density of 0.910 g/cm ³ to 0.940 g/cm ³ , and a density of 0.900 g/cm ³ to 0.910 g/cm ³ Very low density polyethylene copolymer (VLDPE or ULDPE).

The molecular weight distribution index of the ethylene copolymer prepared by the method of the present invention is 2.8-30.0.

The present invention is designed such that the processability of ethylene copolymers (characterized by narrower molecular weight distributions) prepared using conventional single site catalysts is improved due to the fact that the polymers obtained by the multi-step reaction process have an at least bimodal molecular weight distribution. Therefore, the molecular weight distribution index (weight-average molecular weight divided by number-average molecular weight) of the ethylene copolymer prepared by the method and catalyst of the present invention is controlled within the range of 2.8-30.0, thereby improving processability and physical properties.

Therefore, the ethylene copolymer prepared by the above steps (a) and (b) may be an ethylene copolymer having a molecular weight distribution index of 2.8-3.0, preferably 3.0-20. When the molecular weight distribution index is within this range, the processability or physical properties of the ethylene copolymer can be appropriately controlled as required. If the molecular weight distribution index is less than 2.8, there is no significant difference from when using a single reactor and single site catalyst. If the molecular weight distribution index exceeds 30.0, the effect of controlling the density and the molecular weight distribution index disappears, resulting in poor improvement in processability or physical properties.

According to the invention, ethylene and C3-C18 alpha-olefin comonomers (supplied to step (a) or (b)) are dissolved in a solvent before being fed to the reactor. Prior to mixing and dissolving, the ethylene, comonomer and solvent are subjected to a purification process to remove impurities including moisture, oxygen, carbon monoxide and other metal impurities which can be potential catalyst poisons. Substances used for such purification include molecular sieves, activated aluminum and silica gel which are well known in the corresponding art.

The substances to be introduced into steps (a) and (b) are cooled or heated by heat exchange before feeding. The temperature inside the reactor is controlled through this process. Therefore, the temperature control of the reactor is an adiabatic reactor method without heat exchange through the reactor wall. Control of the heat of reaction varies the temperature of the solvent stream entering the reactor and the temperature of the monomer stream.

After step (b), ethylene, comonomers, catalysts or solvents may be additionally supplied according to the invention. The temperature of these components can also be controlled at a predetermined temperature by heat exchange. Usually, the catalyst is supplied separately from other substances, and is preferably mixed with or dissolved in a solvent in advance.

Analysis of molecular weight and density at this step after step (b) [when the polymer is produced in 2 or more steps]; or analysis of polymer produced through other steps by sampling the resin after step (a) and analyze the physical properties of the polymer finally generated after step (b), thereby calculating the density and molecular weight of the polymer in each step.

For the determination of physical properties, analogies can be made from the physical properties of polymers obtained by performing reactions in each step in a single reactor under the same polymerization conditions (such as temperature and pressure, solvent, reactant, catalyst, and reaction time). In addition, the physical properties of the polymer synthesized in each step can be analyzed by sampling and analyzing the samples in the reactor of each step in the multi-step reaction.

Meanwhile, the residence time in step (a) or (b) can be determined by the planned volume and output per unit time of each step. To maintain operating conditions of material homogeneity, steps (a) and (b) require proper agitation. The final produced ethylene polymer or ethylene copolymer is recovered by suitable solvent removal methods.

beneficial effect

The inventive ethylene copolymer with multimodal molecular weight distribution prepared via multi-step synthesis of ethylene and α-olefin shows the effect of improved physical properties and processability.

The method of the present invention provides high productivity and various applications, and overcomes the disadvantages caused by mixing with other polymers.

Molded articles for use as blown films, cast films, injection moldings, blow moldings or pipes can be obtained from the ethylene copolymers prepared via stages (a) and (b).

The films can be formed as blown or cast films to provide single or multilayer films for packaging. It can be used in shrink film, heavy-duty packaging film, frozen packaging film, automatic packaging film, stretch wrap film or bag, etc.

Description of drawings

The above objects, features and advantages of the present invention as well as other objects, features and advantages will become apparent from the following description of preferred embodiments given in conjunction with the accompanying drawings:

Figure 1 is a schematic diagram of a series of reactors according to a preferred embodiment of the present invention.

Figure 2 is a schematic diagram of a parallel reactor according to a preferred embodiment of the present invention.

Figure 3 shows the molecular weight distribution curve of the ethylene copolymer of Example 2 of the present invention.

[specific description of main components]

11: Feed pump for stage-1 reactor

12: Feed Cooler for Stage-1 Reactor

13: Feed Heater for Stage-1 Reactor

14: Phase-1 Low Temperature Reactor

15: Catalyst feed to stage-1 cryogenic reactor

16: Stage-2 High Temperature Reactors in Series

17: Catalyst feed to stage-2 high temperature reactor

18: Feed pump for stage-2 reactor

19: Feed Cooler for Stage-2 Reactor

20: Feed Heater for Stage-2 Reactor

21: Feed piece for stage-2 reactor

22: Hydrogen feed piece

31: Feed pump for cryogenic reactor

32: Feed pump for high temperature reactor

33: Feed Cooler for Low Temperature Reactor

34: Feed heater for low temperature reactor

35: Feed cooler for high temperature reactor

36: Feed heater for high temperature reactor

37: Low temperature reactor

38: Catalyst feed for cryogenic reactors

39: Catalyst feed for high temperature reactors

40: High temperature reactor

41: Inline Mixer

42: Feed piece for stage-2 reactor

43: Hydrogen feed piece

Detailed ways

Hereinafter, the present invention will be described in detail with reference to examples, but the above examples are not intended to limit the scope of the present invention.

Unless otherwise noted, all experiments for the synthesis of ligands and catalysts were performed under nitrogen atmosphere with standard Schlenk or glove box techniques, organic solvents were used after drying over sodium metal and benzophenone at reflux, and distilled immediately before use. The synthesized ligands and catalysts were analyzed by ¹ H-NMR using a Varian Mercury 300 MHz spectrometer at room temperature.

As a solvent for polymerization, cyclohexane was passed through tubes filled sequentially with Q-5 catalyst (from BASF), silica gel, and activated aluminum, and bubbled with high-purity nitrogen to substantially remove moisture, oxygen, and other catalyst poisons.

Using the polymers thus obtained, films processed by blown film forming equipment and injection molding equipment were prepared. The polymers and films thus obtained were analyzed by the methods described below.

1. Melt flow index (MI)

MI was determined according to ASTM D 2839.

2. Density

Density was determined using a density gradient column according to ASTM D 1505.

3. Melting point (Tm) analysis

Using Dupont DSC2910, Tm was measured under the second heating condition at a rate of 10° C./min in the presence of nitrogen atmosphere.

4. Molecular weight and molecular weight distribution

Molecular weight was determined at 135°C at a rate of 1.0 mL/min in the presence of 1,2,3-trichlorobenzene solvent using a PL210GPC equipped with PL Mixed-BX2+preCol. Molecular weights were calibrated using PL polystyrene standards.

5. Tensile strength

Tensile strength was determined according to ASTM D638.

6. Impact strength

Impact strength was determined according to ASTM D1709.

7. Haze

Haze was measured according to ASTM D1003.

8. Heat sealing temperature

The ethylene copolymers obtained in Examples and Comparative Examples were processed into films. 2 sheets of film are overlapped and bonded at a certain temperature with a pressure of 2kgf/ ^cm2 for 1 second. The tensile strength of the bonded samples was determined. If the tensile strength is not less than 1,500 g, the bonding temperature is determined as the heat-sealing temperature. Therefore, the lower the value, the less energy is consumed and high strength is exhibited when used after the bonding process.

9. Processing load

When the product was processed through an extruder having a diameter of 35 mm, the value of current applied to the motor of the extruder was measured as a processing load.

10. Physical properties of the tube

To determine the suitability and merits of the resulting resins for use as pipes, the resins were processed into pipes (outer diameter = 16 mm, thickness = 1.45 mm) and resistance to slow crack growth was determined according to ISO 13479.

All procedures related to the examples were carried out by the continuous solution polymerization method described below. In this process, any solvent stream, monomer stream, or catalyst stream, etc. is provided continuously. Reaction products including polymer, separated solvent and unreacted substances are also continuously removed. All feed streams were passed through commonly known adsorption media to increase purity before being fed to the reactor. During this procedure, impurities (water, oxygen or carbon monoxide, etc.) that are catalyst poisons are removed. All raw materials were stored and used under a high-purity nitrogen atmosphere.

The polymerization method of the present invention is carried out in two reactors connected in series sequentially, or in two reactors connected in parallel. In the case of series, the first reactor has an internal volume of 500 mL and is sequentially connected to a second reactor with a volume of 1000 mL through a tube. In the parallel case, a 500 mL reactor was connected to a 650 mL reactor. Each reactor is designed so that it can be supplied with solvent, monomer, comonomer, hydrogen and catalyst.

The catalyst supplied to the reactor of the present invention is a catalyst composition containing a single-site catalyst represented by the chemical formula (1), and the catalyst is commonly used in the reactions of the first and second stages of all Examples.

As cocatalysts, the present invention uses boron-containing ionic activators and aluminoxanes. In particular, in an embodiment, triisobutylaluminum is optionally used as the aluminoxane and triphenylcarbenium tetrakis(pentafluorophenyl)borate is used as the ionic activator. Catalyst and cocatalyst were supplied to the first and second reactors as solutions dissolved in toluene.

The polymerization method of the present invention is carried out in a cyclohexane solvent under a pressure of 110 kgf/cm ² . Ethylene was dissolved in cyclohexane at a temperature of 23° C. and a pressure of 30 kgf/cm ² before being supplied to a polymerization reactor. The comonomer together with ethylene is also dissolved in the solvent before feeding to the polymerization reactor. As the reaction progresses, the ethylene conversion rate is controlled by catalyst concentration, reaction temperature and catalytic activity.

Catalyst preparation

[Preparation Example 1]

Synthesis of bis(2-phenyl-4-fluorophenoxy)(pentamethylcyclopentadienyl)titanium(IV) chloride

2-Phenyl-4-fluorophenol (1.90 g, 10.09 mmol) was dissolved in diethyl ether (80 mL), and butyl lithium (4.8 mL, 2.5 M in hexane) was slowly added dropwise thereto at 0°C. After reacting at ambient temperature for 5 hours, (trichloro)(pentamethylcyclopentadienyl)titanium(IV) (1.64 g, 5.5 mmol) in 10 mL of diethyl ether was slowly added dropwise thereto at -78°C solution. The mixture was stirred at ambient temperature for 12 hours, then filtered and evaporated to remove volatiles. Recrystallization from a toluene/hexane mixture at -35°C gave an orange solid (2.54 g).

Yield: 85%

¹ H NMR (C ₆ D ₆ ) δ=1.46 (s, 15H), 6.65-7.57 (m, 8H).

[Preparation Example 2]

Synthesis of bis(4-methyl-2-(2'-isopropylphenyl)phenoxy)(pentamethylcyclopentadienyl)titanium(IV) chloride

4-Methyl-2-(2'-isopropylphenyl)phenol (2 g, 8.8 mmol) and sodium hydride (636 mg, 26.5 mmol) were dissolved in toluene (20 mL), and the mixture was refluxed for 4 hours. The reaction mixture was then cooled to ambient temperature, to which a solution of (pentamethylcyclopentadienyl)titanium(IV) trichloride (115 g, 4.0 mmol) dissolved in 5 mL of toluene was slowly added dropwise. The resulting mixture was refluxed for 24 hours. At the end of the reaction, the volatiles were removed and the residue was washed with pure hexane. It was recrystallized from hexane at -35°C, and dried under reduced pressure to obtain an orange solid (1.65 g).

Yield 61%

¹ H NMR (C ₆ D ₆ ) δ=0.96-1.07 (m, 6H), 1.54 (s, 15H), 1.72 (s, 3H), 2.76 (m, 1H), 6.76-7.27 (m, 7H) ppm

[Preparation Example 3]

Synthesis of bis(2-phenylphenoxy)(pentamethylcyclopentadienyl)titanium(IV) chloride

In a dry flask, 2-phenylphenol (1.72 g, 10.1 mmol, Aldrich 99%) was dissolved in 40 mL of toluene. The solution was cooled to 0° C. and stirred thoroughly, to which n-butyllithium (4.8 mL, 2.5 M in hexane, Aldrich) was added slowly. After maintaining this temperature for 1 hour, a solution of pentamethylcyclopentadienyltitanium trichloride (1.64 g, 55 mmol) in 10 mL of toluene was slowly added thereto. After maintaining this temperature for 1 hour, the temperature was raised to ambient temperature and the reaction mixture was stirred for a further 1 hour. The reactor temperature was raised to 90°C, and the reaction was carried out for 12 hours. The mixture was filtered, evaporated to remove volatiles, and recrystallized from a mixed solvent of toluene/hexane at -35°C to obtain an orange solid (2.3 g).

Yield: 75%

¹ H NMR (C ₆ D ₆ )δ=1.54(s, 15H), 6.74～7.16(m, 9H)ppm

[Preparation Example 4]

Synthesis of 2-isopropyl-6-phenylphenol

In 2-bromo-6-isopropylanisole (1.98g, 8.64mmol), phenylboronic acid (2.10g, 17.28mmol), palladium acetate (96mg, 0.43mmol), triphenylphosphine (0.225g, 0.86mmol) and potassium phosphate (11g, 51.84mmol), a mixture of water (8mL) and dimethoxyethane (32mL) was added, and the resulting mixture was heated under reflux for 12 hours. After cooling to ambient temperature, aqueous ammonium chloride (15 mL) and diethyl ether (30 mL) were added thereto. The organic layer was separated and the residue was extracted with ether. The combined organic layers were dried over magnesium sulfate and evaporated to remove volatiles to give 2-isopropyl-6-phenylanisole (2 g) as a gray solid. The obtained anisole (without further purification) was dissolved in dichloromethane (15 mL), and 12 mL of boron tribromide solution (1M in dichloromethane) was added dropwise thereto at -78°C. While slowly warming to ambient temperature, the reaction was carried out for 12 hours. When the reaction was complete, a mixture of water (15 mL) and diethyl ether (30 mL) was added thereto. The organic layer was separated, and the aqueous layer was extracted with ether (15 mL×3). The combined organic layers were dried and evaporated under reduced pressure to remove volatiles. The residue was purified through a silica gel column using a mixed solvent of hexane and dichloromethane to obtain 2-isopropyl-6-phenylphenol (1.72 g) as a white solid.

Yield: 94%

¹ H-NMR (CDCl ₃ ) δ = 1.307 (d, 6H), 3.45 (m, 1H), 5.09 (s, 1H), 6.95-7.43 (m, 8H) ppm

Synthesis of (dichloro)(pentamethylcyclopentadienyl)(2-isopropyl-6-phenylphenoxy)titanium(IV)

A solution of 2-isopropyl-6-phenylphenol (700 mg, 3.28 mmol) and sodium hydride (236 mg, 9.84 mmol) in toluene (10 mL) was reacted at reflux for 4 hours. The mixture was then cooled to ambient temperature, to which a solution of (trichloro)(pentamethylcyclopentadienyl)titanium(IV) (930 mg, 3.21 mmol) dissolved in toluene (5 mL) was slowly added dropwise. The resulting mixture was refluxed for 24 hours. When the reaction was completed, volatile substances were removed therefrom, and the residue was washed with purified hexane. Recrystallization was performed at -35°C with a mixed solvent of toluene/hexane, and then filtered and dried under reduced pressure to obtain a red solid (1.0 g).

Yield: 64%

¹ H-NMR (C ₆ D ₆ ) δ=1.324 (d, 6H), 1.63 (s, 15H), 3.53 (m, 1H), 7.05-7.66 (m, 8H) ppm

[Preparation Example 5]

Synthesis of 2-diphenylphenol

In 2-bromoanisole (1.62g, 8.64mmol), 4-diphenylboronic acid (2.57g, 12.96mmol), palladium acetate (96mg, 0.43mmol), triphenylphosphine (0.225g, 0.86mmol) A mixture of water (8 mL) and dimethoxyethane (32 mL) was added to a flask with potassium phosphate (11 g, 51.84 mmol), and the resulting mixture was heated at reflux for 12 hours. After cooling to ambient temperature, aqueous ammonium chloride (15 mL) and diethyl ether (30 mL) were added thereto. The organic layer was separated and the residue was extracted with ether. The combined organic layers were dried over magnesium sulfate and evaporated to remove volatiles to give 2-diphenylanisole (2.0 g) as a gray solid. The obtained anisole (without further purification) was dissolved in dichloromethane (15 mL), and 12 mL of boron tribromide solution (1M in dichloromethane) was added dropwise thereto at -78°C. While slowly warming to ambient temperature, the reaction was carried out for 12 hours. When the reaction was complete, a mixture of water (15 mL) and diethyl ether (30 mL) was added thereto. After separating the organic layer, the aqueous layer was extracted with ether (15 mL×3). The combined organic layers were dried and evaporated under reduced pressure to remove volatiles. The residue was purified through a silica gel column using a mixed solvent of hexane and dichloromethane to obtain 2-diphenylphenol (1.8 g) as a white solid.

Yield: 85%

¹ H-NMR (CDCl ₃ ) δ=5.29 (s, 1H), 6.95-7.75 (m, 13H) ppm

Synthesis of (dichloro)(pentamethylcyclopentadienyl)(2-diphenylphenoxy)titanium(IV)

A solution of 2-diphenylphenol (700 mg, 2.84 mmol) and sodium hydride (204 mg, 8.52 mmol) in toluene (10 mL) was reacted at reflux for 4 hours. The mixture was then cooled to ambient temperature, to which a solution of (trichloro)(pentamethylcyclopentadienyl)titanium(IV) (820 mg, 2.83 mmol) dissolved in toluene (5 mL) was slowly added dropwise. The resulting mixture was refluxed for 24 hours. When the reaction was completed, volatile substances were removed therefrom, and the residue was washed with purified hexane. Recrystallization was performed at -35°C with a mixed solvent of toluene/hexane, and then filtered and dried under reduced pressure to obtain a red solid (0.9 g).

Yield: 64%

¹ H-NMR (C ₆ D ₆ )δ=1.65 (s, 15H), 6.65-7.89 (m, 13H) ppm

[Preparation Example 6]

Synthesis of (dichloro)(pentamethylcyclopentadienyl)(2-9',9"-dimethylfluoren-2'-yl)phenoxy)titanium(IV)

Synthesis of 2-bromo-9,9'-dimethylfluorene

A 1000 mL three-neck round bottom flask was charged with 2-bromofluorene (25 g, 102.0 mmol), iodoethane (43.4 g, 306.0 mmol) and DMSO (300 mL), and the mixture was stirred under nitrogen atmosphere to obtain complete dissolution. A solution of potassium tert-butoxide (32.1 g, 285.6 mmol) dissolved in DMSO (400 mL) was slowly added dropwise thereto. Stirring was carried out for 12 hours at ambient temperature and for a further 1 hour at 80°C. The temperature was lowered to ambient temperature again, the reaction mixture was mixed with water (1000 mL), and extracted with n-hexane. The organic mixture was washed 3 times with distilled water, and dried over anhydrous magnesium sulfate (MgSO ₄ ) to remove water. After evaporating the solvent with a rotary evaporator, the residue was purified by silica gel column chromatography using n-hexane. Recrystallization from n-hexane gave 2-bromo-9,9'-dimethylfluorene (27.0 g, yield: 96.9%) as a white solid.

¹ H-NMR(CDCl ₃ )δ=1.65(s, 6H), 7.35-7.39(m, 2H), 7.44-7.50(m, 2H), 7.58-7.62(m, 2H), 7.72-7.73(m, 1H)ppm

Synthesis of 2-(2”-methoxyphenyl)-9,9’-dimethylfluorene

Equipped with 2-bromo-9,9'-dimethylfluorene (27.0g, 98.8mmol), 2-methoxyphenylboronic acid (18.0g, 118.6mmol), palladium acetate (0.13g, 0.6mmol), In a flask of triphenylphosphine (0.94g, 3.6mmol) and potassium phosphate (40.9g, 177.9mmol), a mixture of water (70mL) and dimethoxyethane (150mL) was added, and the resulting mixture was heated under reflux for 6 hours . After cooling to ambient temperature, aqueous ammonium chloride (150 mL) and diethyl ether (200 mL) were added thereto. The organic layer was separated, and the residue was extracted with ether. The combined organic layers were dried over magnesium sulfate and evaporated to remove volatiles. Purification by silica gel column chromatography (eluent: hexane) gave the solid product 2-(2"-methoxyphenyl)-9,9'-dimethylfluorene (28.0 g, yield: 94.0%).

¹ H-NMR (CDCl ₃ ) δ=1.56(s, 6H), 3.88(s, 3H), 7.04-7.06(d, 1H), 7.08-7.11(t, 1H), 7.33-7.39(m, 3H) , 7.43-7.45(d, 1H), 7.47-7.48(d, 1H), 7.56-7.58(d, 1H), 7.63(s, 1H), 7.76-7.840(t, 2H)ppm

Synthesis of 2-(9',9"-Dimethylfluorene 2'-yl)phenol

2-(2"-methoxyphenyl)-9,9'-dimethylfluorene (25.0 g, 83.2 mmol) was dissolved in dichloromethane (400 mL), and 100 mL was added dropwise thereto at -78°C Boron tribromide solution (1M in dichloromethane). While slowly warming up to ambient temperature, the reaction was carried out for 3 hours. When the reaction was complete, a mixture of ice (150 g) and diethyl ether (300 mL) was added thereto. The organic After the layers, the aqueous layer was extracted with diethyl ether. The combined organic layers were dried over magnesium sulfate, and evaporated to remove volatile substances. The residue was purified by silica gel column chromatography using a mixed solvent of hexane and dichloromethane to obtain a white solid 2- (9',9"-dimethylfluoren-2'-yl)phenol (18.0 g, yield: 75.5%).

¹ H-NMR(CDCl ₃ )δ=1.55(s, 6H), 7.04-7.07(m, 2H), 7.30-7.40(m, 4H), 7.47-7.50(m, 2H), 7.55(s, 1H) , 7.78-7.80 (d, 1H), 7.85-7.87 (d, 1H) ppm

Synthesis of (dichloro)(pentamethylcyclopentadienyl)(2-(9',9"-dimethylfluoren-2'-yl)phenoxy)titanium(IV)

Into a solution of 2-(9',9"-dimethylfluoren-2'-yl)phenol (5.0 g, 17.1 mmol) dissolved in 200 mL of toluene at -78°C, n-butyllithium (2.5 M hexyl alkane solution, 6.9mL). After the mixture was stirred at ambient temperature for 12 hours, the reaction mixture was cooled to -78°C, and (pentamethylcyclopentadienyl)titanium(IV) trichloride (4.7g , 16.3 mmol) was dissolved in 100 mL of toluene, and the reaction was continued at ambient temperature for 12 hours. When the reaction was complete, the reaction mixture was filtered through celite, and the solvent was removed. At -35 ° C with purified toluene and hexane The alkane was recrystallized, then filtered and dried under reduced pressure to obtain a red solid (dichloro)(pentamethylcyclopentadienyl)(2-(9',9"-dimethylfluoren 2'-yl)phenoxy ) Titanium(IV) (5.6 g, yield: 63.9%).

¹ H-NMR (C ₆ D ₆ ) δ=1.61(s, 6H), 1.77(s, 15H), 7.03-7.05(t, 1H), 7.16-7.19(t, 1H), 7.32-7.34(m, 2H), 7.37-7.39(d, 1H), 7.42-7.44(d, 1H), 7.46-7.47(d, 1H), 7.71-7.77(m, 3H), 7.82-7.84(d, 1H)ppm

Mass (APCI mode, m/z): 539.4

[Preparation Example 7]

Synthesis of (chloro)(pentamethylcyclopentadienyl)(bis(2-(9',9"-dimethylfluorene 2'-yl)phenoxy))titanium(IV)

Into a solution of 2-(9',9"-dimethylfluoren-2'-yl)phenol (5.0 g, 17.1 mmol) dissolved in 200 mL of toluene at -78°C, n-butyllithium (2.5 M hexyl alkane solution, 6.9 mL). After the mixture was stirred at ambient temperature for 12 hours, the reaction mixture was cooled to -78 ° C, and (pentamethylcyclopentadienyl) titanium(IV) trichloride (2.3 g , 8.0 mmol) was dissolved in 100 mL of toluene, and the reaction was continued at 80°C for 12 hours. When the reaction was complete, the reaction mixture was filtered through celite, and the solvent was removed. Reconstitution was carried out at -35°C with pure toluene and hexane Crystallized, then filtered and dried under reduced pressure to give an orange solid as (chloro)(pentamethylcyclopentadienyl)(bis(2-(9',9"-dimethylfluoren2'-yl)phenoxy) Titanium (IV) (3.5 g) (yield: 55.8%).

¹ H-NMR (C ₆ D ₆ ) δ=1.54(s, 6H), 1.61(s, 6H), 1.65(s, 15H), 7.01-7.04(t, 2H), 7.21-7.24(t, 2H) , 7.33-7.36(m, 4H), 7.39-7.41(t, 4H), 7.44-7.46(m, 2H), 7.65(s, 2H), 7.73-7.757(t, 2H), 7.82-7.88(m, 4H)ppm

Mass (APCI mode, m/z): 789.3

[Preparation Example 8]

Synthesis of (dichloro)(pentamethylcyclopentadienyl)(2-(9'H-fluoren-2'-yl)phenoxy)titanium(IV)

Synthesis of 2-(2'-methoxyphenyl)-9H-dimethylfluorene

In a solution containing 2-bromo-9H-fluorene (10.0g, 40.8mmol), 2-methoxyphenylboronic acid (7.4g, 49.0mmol), palladium acetate (0.055g, 0.245mmol), triphenylphosphine (0.44 g, 1.4 mmol) and potassium phosphate (2.0 g, 95.5 mmol), a mixture of water (33 mL) and dimethoxyethane (100 mL) was added, and the resulting mixture was heated under reflux for 6 hours. After cooling to ambient temperature, aqueous ammonium chloride (100 mL) and diethyl ether (150 mL) were added thereto. The organic layer was separated, and the residue was extracted with ether. The combined organic layers were dried over magnesium sulfate and evaporated to remove volatiles. Purification by silica gel column chromatography (eluent: hexane) gave the solid product 2-(2'-methoxyphenyl)-9H-dimethylfluorene (10.0 g, yield: 90.0%).

¹ H-NMR(CDCl ₃ )δ=3.87(s, 3H), 3.98(s, 2H), 7.04-7.05(d, 1H), 7.07-7.10(t, 1H), 7.32-7.42(m, 4H) , 7.57-7.59 (d, 2H), 7.74 (s, 1H), 7.83-7.86 (t, 2H) ppm

Synthesis of 2-(9'H-fluorene 2'-yl)phenol

2-(2'-Methoxyphenyl)-9H-dimethylfluorene (10.0 g, 36.7 mmol) was dissolved in dichloromethane (200 mL), and 44 mL of tribromide was added dropwise thereto at -78 °C Boron solution (1M in dichloromethane). The reaction was carried out for 3 hours while slowly warming to ambient temperature. When the reaction was complete, a mixture of ice (150 g) and diethyl ether (200 mL) was added thereto. After separation of the organic layer, the aqueous layer was extracted with ether. The combined organic layers were dried over magnesium sulfate and evaporated to remove volatiles. The residue was purified via silica gel column chromatography using a mixed solvent of hexane and dichloromethane to obtain white solid 2-(9'H-fluorene 2'-yl)phenol (7.0 g, yield: 73.8%).

¹ H-NMR(CDCl ₃ )δ=3.96(s, 2H), 7.00-7.02(m, 2H), 7.25-7.35(m, 3H), 7.39-7.42(t, 1H), 7.47-7.49(d, 1H), 7.56-7.58(d, 1H), 7.64(s, 1H), 7.81-7.83(d, 1H), 7.88-7.89(d, 1H)ppm

Synthesis of (dichloro)(pentamethylcyclopentadienyl)(2-(9'H-fluoren2'-yl)phenoxy)titanium(IV)

Into a solution of 2-(9'H-fluorene 2'-yl)phenol (4.4g, 17.0mmol) dissolved in 200mL toluene at -78°C, slowly inject n-butyllithium (2.5M in hexane, 6.9mL ). After the mixture was stirred at ambient temperature for 12 hours, the reaction mixture was cooled to -78°C, and (pentamethylcyclopentadienyl)titanium(IV) trichloride (4.7 g, 16.3 mmol) dissolved in 100 mL was slowly added thereto solution in toluene and the reaction was continued at ambient temperature for 12 hours. When the reaction was complete, the reaction mixture was filtered through celite, and the solvent was removed. Recrystallized from purified toluene and hexane at -35°C, then filtered and dried under reduced pressure to obtain a red solid (dichloro)(pentamethylcyclopentadienyl)(2-(9'H-fluorene 2'- (yl)phenoxy)titanium(IV) (5.9 g) (yield: 71.0%).

¹ H-NMR (C ₆ D ₆ ) δ=1.72(s, 15H), 3.94(s, 2H), 7.05-7.18(m, 2H), 7.36-7.38(m, 2H), 7.44-7.46(m, 2H), 7.48-7.50(d, 1H), 7.65-7.66(d, 1H), 7.81-7.82(d, 1H), 7.86-7.87(d, 1H), 7.98(1, 1H)ppm

Mass (APCI mode, m/z): 511.3

[Preparation Example 9]

Synthesis of (dichloro)(pentamethylcyclopentadienyl)(1-phenylnaphth-2-yloxy)titanium(IV)

Synthesis of 1-bromo-2-methoxynaphthalene

Charge 1-bromonaphthalene-2-ol (30.0 g, 134.5 mmol), potassium hydroxide (KOH) (11.3 g, 201.7 mmol) and DMSO (300 mL) in a 500 mL three-necked round bottom flask, and place the mixture in a nitrogen atmosphere Stir for 10 minutes. After cooling the mixture with an ice-water bath, ethyl iodide (28.6 g, 201.7 mmol) was slowly added dropwise thereto. The resulting mixture was then stirred under a nitrogen atmosphere at ambient temperature for 12 hours, then at 50°C for 1 hour. After cooling to ambient temperature, the reaction mixture was mixed with water (500 mL) and extracted with ether. The organic mixture was washed 3 times with distilled water and dried over anhydrous magnesium sulfate (MgSO ₄ ). After removing the solvent using a rotary evaporator, the residue was purified by silica gel column chromatography (eluent: n-hexane) to obtain a white solid sample 1-bromo-2-methoxynaphthalene (22.0 g, yield: 69.0% ).

¹ H-NMR(CDCl ₃ )δ=4.07(s, 3H), 7.30-7.32(d, 1H), 7.41-7.44(t, 1H), 7.58-7.61(t, 1H), 7.81-7.86(m, 2H), 8.25-8.26(d, 1H)ppm

Synthesis of 2-methoxy-1-phenylnaphthalene

In 1-bromo-2-methoxynaphthalene (20.0g, 84.4mmol), phenylboronic acid (11.3g, 92.8mmol), palladium acetate (0.10g, 0.46mmol), triphenylphosphine (0.85g, 2.78mmol) and potassium phosphate (40.9g, 177.9mmol), a mixture of water (60mL) and dimethoxyethane (120mL) was added, and the resulting mixture was heated under reflux for 6 hours. After cooling to ambient temperature, aqueous ammonium chloride (150 mL) and diethyl ether (200 mL) were added thereto. The organic layer was separated, and the residue was extracted with ether. The combined organic layers were dried over magnesium sulfate and evaporated to remove volatiles. Purification via silica gel column chromatography (eluent: hexane) gave 2-methoxy-1-phenylnaphthalene (13.0 g, yield: 66%) as a colorless liquid.

¹ H-NMR(CDCl ₃ )δ=3.87(s, 3H), 7.35-7.47(m, 6H), 7.52-7.55(m, 3H), 7.85-7.87(d, 1H), 7.91-7.93(d, 1H)ppm

Synthesis of 1-Phenylnaphth-2-ol

2-Methoxy-1-phenylnaphthalene (13.0 g, 55.5 mmol) was dissolved in dichloromethane (300 mL), and 670 mL of boron tribromide solution (1M dichloromethane solution). The reaction was carried out for 3 hours while slowly warming to ambient temperature. When the reaction was complete, a mixture of ice (150 g) and diethyl ether (250 mL) was added thereto. After separation of the organic layer, the aqueous layer was extracted with ether. The combined organic layers were dried over magnesium sulfate and evaporated to remove volatiles. The residue was purified via silica gel column chromatography using a mixed solvent of hexane and dichloromethane to obtain 1-phenylnaphth-2-ol (10.0 g, yield: 81.8%) as a white solid.

¹ H-NMR (CDCl ₃ ) δ=7.29-7.31 (d, 1H), 7.35-7.39 (m, 2H), 7.53-7.56 (t, 1H), 7.61-7.64 (t, 2H), 7.83-7.86 ( m, 2H)ppm

Synthesis of (dichloro)(pentamethylcyclopentadienyl)(1-phenylnaphth-2-yloxy)titanium(IV)

To a solution of 1-phenylnaphth-2-ol (2.0 g, 9.1 mmol) in 100 mL of toluene at -78°C was slowly injected n-butyllithium (2.5 M in hexane, 3.6 mL). After the mixture was stirred at ambient temperature for 12 hours, the reaction mixture was cooled to -78°C, and (pentamethylcyclopentadienyl)titanium(IV) trichloride (2.5 g, 16.3 mmol) dissolved in 60 mL was slowly added thereto solution in toluene and the reaction was continued at ambient temperature for 12 hours. When the reaction was complete, the reaction mixture was filtered through celite, and the solvent was removed. Recrystallized from purified toluene and hexane at -35°C, then filtered and dried under reduced pressure to obtain a red solid (dichloro)(pentamethylcyclopentadienyl)(1-phenylnaphth-2-yloxy) Titanium (IV) (2.5 g) (yield: 58.2%).

¹ H-NMR (C ₆ D ₆ ) δ=1.87 (s, 15H), 7.27-7.32 (m, 3H), 7.43-7.46 (t, 2H), 7.58-7.60 (m, 3H), 7.70-7.73 ( t, 1H), 7.92-7.94 (t, 1H) ppm

Mass (APCI mode, m/z): 471.83

Example 1

For the single-site catalyst of the stage-1 and stage-2 reactors in series, bis(pentamethylcyclopentadienyl)(2-phenyl-4-fluorophenoxy)chlorination prepared in Preparation Example 1 was used Titanium(IV). The amounts of catalysts used in Examples and Comparative Examples are shown in Tables 1 and 2. Ti represents a single-site catalyst, Al represents triisobutylaluminum as a cocatalyst, and B represents triphenylcarbenium tetrakis(pentafluorophenyl)borate. Each catalyst was dissolved in xylene at a concentration of 0.2 g/L, 5.0 g/L or 1.5 g/L. For each reactor, the ethylene feed ratio was 4:6 and 1-octene was used as comonomer. However, when the conversion is low, the amount of ethylene fed to the stage-2 reactor should be determined taking into account the amount of unreacted ethylene flowing into the second reactor to adjust the polymer density and molecular weight from the first reactor . From the reaction conditions used to polymerize one type of polymer and the temperature gradient in the reactor, the conversion of each reactor can be estimated for each reaction condition. In order to produce copolymers with higher MI in the second reactor, an appropriate amount of hydrogen was injected to control the molecular weight. In addition, the molecular weight of each reactor can be controlled according to the reactor temperature and 1-octene content, the situation is shown in Table 1-1.

The ethylene copolymer thus prepared was extruded at a barrel temperature of 160-170-170° C. and a die temperature of 175° C. to produce a blown film having a thickness of 40 μm and a width of 530 μm.

Example 2

The polymer is prepared according to the procedure described in Example 1, except that two (2-phenylphenoxy) (pentamethylcyclopentadiene) synthesized in Preparation Example 3 dissolved in toluene at a concentration of 0.2 g/L base) Ti(IV) chloride was introduced as a single-site catalyst (the amounts are shown in Table 1). Under the conditions listed in Table 1-1, polymers were produced with different amounts of ethylene fed to each reactor, different amounts of 1-octene as a comonomer, and different temperature conditions of the reactors.

Fig. 3 is the molecular weight distribution curve of the ethylene copolymer of Example 2 of the present invention. Referring to FIG. 3 , since the molecular weight distribution curve of the ethylene copolymer of Example 2 of the present invention shows a bimodal (3.58), it can be confirmed that the polymer has a broad molecular weight distribution.

The ethylene copolymer thus obtained was prepared as a blown film under the same conditions as in Example 1.

Example 3

The reaction was carried out using two reactors connected in parallel. The polymer solution and solvent from each reactor were homogeneously mixed via an in-line mixer to prepare a polymer product.

Two (4-methyl-2-(2'-isopropylphenyl) phenoxy) (pentamethylcyclopentadienyl) (pentamethylcyclopentadienyl) synthesized by Preparation Example 2 dissolved in toluene at a concentration of 0.2g/L Titanium(IV) chloride was added as a single-site catalyst in the amount shown in Table 1-1. As shown in Table 1-1, polymers were produced using different amounts of ethylene supplied to each reactor, different amounts of 1-octene as a comonomer, and different temperature conditions of the reactors.

The ethylene copolymer thus obtained was prepared as a blown film under the same conditions as in Example 1.

Example 4

The polymer was prepared according to the procedure described in Example 3, except that the amount of single-site catalyst supplied to the first and second reactors was as shown in Table 1-1. As shown in Table 1-1, polymers were prepared using different amounts of ethylene, different amounts of 1-octene as a comonomer, and different temperature conditions of the reactor.

The ethylene copolymer thus prepared was extruded by film molding at a barrel temperature of 160-180-200°C and a mold temperature of 230°C to prepare a cast film with a thickness of 40 μm and a width of 445 μm.

Example 5

The polymer is prepared according to the procedure described in Example 1, except that the (dichloro)(pentamethylcyclopentadienyl)(2-iso Propyl-6-phenylphenoxy)titanium(IV) was introduced as a single-site catalyst into the first and second reactors (the amounts are shown in Table 1-1). Under the conditions listed in Table 1-1, polymers were produced with different amounts of ethylene fed to each reactor, different amounts of 1-octene as a comonomer, and different temperature conditions of the reactors.

The ethylene copolymer thus obtained was prepared as a cast film under the same conditions as in Example 4.

Example 6

The polymer was prepared according to the procedure described in Example 3, except that (dichloro)(pentamethylcyclopentadienyl)(2-di Phenylphenoxy)titanium(IV) was introduced as a single-site catalyst into the first and second reactors (the amount is shown in Table 1-1). Under the conditions listed in Table 1-1, polymers were produced with different amounts of ethylene fed to each reactor, different amounts of 1-octene as a comonomer, and different temperature conditions of the reactors.

The ethylene copolymer thus obtained was prepared as a cast film under the same conditions as in Example 4.

Example 7

The polymer is prepared according to the procedure described in Example 1, except that two (2-phenylphenoxy) (pentamethylcyclopentadiene) synthesized in Preparation Example 3 dissolved in toluene at a concentration of 0.2 g/L Base) titanium(IV) chloride was introduced as a single-site catalyst into the first and second reactors (the amount is shown in Table 1-1). Under the conditions listed in Table 1-1, polymers were produced with different amounts of ethylene fed to each reactor, different amounts of 1-octene as a comonomer, and different temperature conditions of the reactors.

The ethylene copolymer thus prepared is extruded using a pipe extruder at a line speed of 5 m/min, at a barrel temperature of 160-200-220° C. and a die temperature of 230° C. to obtain an outer diameter of 16 mm and a thickness of 1.45 mm. mm tube.

Example 8

The polymer is prepared according to the procedure described in Example 1, except that the (dichloro) (pentamethylcyclopentadienyl) (2-( 9'9"-dimethylfluorene 2'-yl)phenoxy)titanium(IV) was introduced as a single-site catalyst into the first and second reactors (amounts shown in Table 1-2). In Table 1-2 Under the conditions listed, polymers were produced with different amounts of ethylene fed to each reactor, different amounts of 1-octene as comonomer, and different temperature conditions of the reactors.

The ethylene copolymer thus obtained was prepared as a cast film under the same conditions as in Example 4.

Example 9

The polymer is prepared according to the procedure described in Example 1, except that the (chloro) (pentamethylcyclopentadienyl) (two (2- (9'9"-dimethylfluoren-2'-yl)phenoxy)titanium(IV) was introduced as a single-site catalyst into the first and second reactors (in amounts shown in Table 1-2). In Table 1 - Under the conditions listed in -2, polymers were produced with different amounts of ethylene fed to each reactor, different amounts of 1-octene as a comonomer, and different temperature conditions of the reactors.

The ethylene copolymer thus obtained was prepared as a cast film under the same conditions as in Example 4.

Example 10

The polymer is prepared according to the procedure described in Example 1, except that the (dichloro)(pentamethylcyclopentadienyl) (2-( 9'H-fluoren-2'-yl)phenoxy)titanium(IV) was introduced as a single-site catalyst into the first and second reactors (the amounts are shown in Tables 1-2). Under the conditions listed in Tables 1-2, polymers were produced with different amounts of ethylene fed to each reactor, different amounts of 1-octene as a comonomer, and different temperature conditions of the reactors.

The ethylene copolymer thus obtained was prepared as a cast film under the same conditions as in Example 4.

Example 11

The polymer was prepared according to the procedure described in Example 1, except that the (dichloro)(pentamethylcyclopentadienyl)(1-benzene) synthesized in Preparation Example 9 dissolved in toluene at a concentration of 0.2 g/L was Naphthalene-2-yloxy)titanium(IV) was introduced as a single-site catalyst into the first and second reactors (the amounts are shown in Tables 1-2). Under the conditions listed in Tables 1-2, polymers were produced with different amounts of ethylene fed to each reactor, different amounts of 1-octene as a comonomer, and different temperature conditions of the reactors.

The ethylene copolymer thus obtained was prepared as a cast film under the same conditions as in Example 4.

Comparative example 1

Prepare the polymer in a single reactor, and dissolve the bis(4-methyl-2-(2'-isopropylphenyl)phenoxy group synthesized in Preparation Example 2 in toluene at a concentration of 0.2g/L )(pentamethylcyclopentadienyl)titanium(IV) chloride was used as a single-site catalyst (amounts shown in Table 2). Under the conditions listed in Table 2, polymers were produced with different amounts of ethylene fed to each reactor, different amounts of 1-octene as a comonomer, and different temperature conditions of the reactors. As with the copolymers produced in Examples 1 to 3, physical properties measured after processing the copolymers into films are shown in Table 3.

Comparative example 2

The polymer was prepared according to the procedure described in Example 1, except that (trimethyl)(pentamethylcyclopentadienyl)titanium(IV) dissolved in toluene at a concentration of 0.5 mol/mL was used as a single-site catalyst For the first and second reactors (amounts shown in Table 2). Under the conditions listed in Table 2, polymers were produced with different amounts of ethylene fed to each reactor, different amounts of 1-octene as a comonomer, and different temperature conditions of the reactors.

As with the copolymers produced in Examples 1 to 3, physical properties measured after processing the copolymers into films are shown in Table 3.

Comparative example 3

Copolymer with 1-octene (FT810 Grade, commercially available from SK Energy) with unimodal molecular weight distribution. As with the copolymers produced in Examples 1 to 3, physical properties measured after processing the copolymers into films are shown in Table 3.

Comparative example 4

Copolymer with 1-octene (FT810 Grade, commercially available from SK Energy) with unimodal molecular weight distribution. As with the copolymers produced in Examples 4 and 5, the physical properties measured after processing the copolymers into films are shown in Table 3.

Comparative Example 5

Copolymer with 1-octene (DX800 Grade, commercially available from SK Energy) with unimodal molecular weight distribution. As with the copolymer produced in Example 6, the physical properties measured after processing the copolymer into tubes are shown in Table 3.

[Table 1-1]

[Table 1-2]

- ratio of ethylene = 1st reactor: 2nd reactor

-Ti: Indicates Ti in a single-site catalyst

-Al: Indicates triisobutylaluminum as a cocatalyst

-B: Represents triphenylcarbenium tetrakis (pentafluorophenyl) borate as a cocatalyst

[Table 2]

[table 3]

[Table 4]

Table 1-1, Table 1-2 and Table 2 show the polymerization conditions of Examples 1 to 11 and Comparative Examples 1 to 5 and the physical properties of the polymers produced under the respective conditions. In Table 1-1, Table 1-2, and Table 2, it was confirmed that the polymer prepared using the single-site catalyst in the 2-step reaction method showed a broad molecular weight distribution of 3 or more. A limited number of examples of the catalysts of the present invention clearly show the characteristics of single site catalysts (albeit with some differences in degree of comonomer coupling and activity). It can be found that the copolymer prepared according to the method proposed in the present invention exhibits more excellent physical properties than conventional products.

Table 3 shows the physical properties of the films prepared in Examples 1-6, 8-11 and Comparative Examples 1 and 2. It can be seen that while the MI and density levels are similar, most of the physical properties of the films of the present invention are improved. In particular, the processing load on the extruder is significantly reduced due to the wider molecular weight distribution, which leads to energy savings and higher production rates during production.

In Examples 1, 2, 3, 8 and 10 and Comparative Example 2, resins synthesized by the same method using different metallocene catalysts were analyzed and blown films processed therefrom were compared. The metallocene catalyst used in Comparative Example 2 does not belong to the scope of the metallocene catalyst of the present invention. Under the corresponding reaction temperature, the ethylene copolymer prepared by the catalyst through the first reactor did not produce a high molecular weight resin, and the blown film thus prepared showed a large difference from the resins of Examples 1, 2, 3, 8 and 10. physical properties.

The effect of the present invention is revealed when blown films prepared according to the present invention (Examples 1-3, 8, 10) are compared with films obtained from a conventional product (FN810 Grade of SK Energy) (Comparative Example 3) . Examples 1-3, 8 and 10 show great improvements in impact strength and heat seal temperature due to the different proportions of the high molecular weight, low density fraction produced by the reactor.

In Examples 4, 5, 6, 9, 11 and Comparative Example 4, resins corresponding to the representative MI and density of cast films synthesized according to the method of the present invention, as well as conventional products (FT810 Grade from SK Energy) were tested. The polymers were analyzed and physical properties were tested after processing into films.

Table 4 shows the test results of the tubes prepared from Example 7 and Comparative Example 5. To examine the improvement of the physical properties of the tubes, slow crack growth was measured according to ISO 13479 at 80°C as described above. The polymers of Example 7 and Comparative Example 5 were individually processed into tubes with an outer diameter of 16 mm and a thickness of 1.45 mm, and hoop stresses of 5.5 MPa and 5.65 MPa were applied thereto at 80° C., respectively. The duration before rupture is recorded.

As can be seen from Table 4, the tubes prepared from Example 7 (in which a high molecular weight, low density fraction was added to the Stage-1 reactor) exhibited enhanced durability.

Although the present invention has been described in detail with reference to the foregoing embodiments and accompanying drawings, those of ordinary skill in the industrial field to which the present invention belongs can make various replacements, improvements or changes without departing from the gist or the present invention defined by the appended claims. scope.

Industrial Applicability

Molded articles such as blown films, cast films, injection moldings, blow moldings or pipes can be obtained from the ethylene copolymers prepared according to the invention.

The films can be formed as blown or cast films to provide single or multilayer films for packaging. It can be used in shrink film, heavy-duty packaging film, freezer packaging film, automatic packaging film, stretch wrap film or bags, etc.

Claims (17)

1. method for preparing ethylene copolymer, described method comprises

(a) in one or more reactors, in the presence of the catalyst composition that contains the transition-metal catalyst that is represented by chemical formula (1), make ethene and one or more C3-C18 alpha-olefin comonomer carry out solution polymerization, thereby produce the first multipolymer; With

(b) with step (a) in used identical catalyst composition in the presence of, in the temperature that is higher than step (a) temperature of reaction, make described the first multipolymer that is prepared by step (a) by containing at least one other reactor of ethene or ethene and at least a C3-C18 alpha-olefin, wherein the amount of step (a) and ethene (b) and one or more C3-C18 alpha-olefin comonomer is the ethene of 60 % by weight～99 % by weight and the alpha-olefin comonomer of 1 % by weight～40 % by weight, thereby prepare the high temperature polymer that contains ethene and C3-C18 alpha-olefin copolymer composition by solution polymerization, so that described ethylene copolymer comprises the polymkeric substance of step (b) preparation of the polymkeric substance of step (a) preparation of 10 % by weight～70 % by weight and 30 % by weight～90 % by weight

[Chemical formula 1]

In this formula, M represents the transition metal of the periodic table of elements the 4th family;

Cp represents η ⁵-being connected to the cyclopentadiene ring of described core metal M or containing the condensed ring of cyclopentadiene ring, wherein said cyclopentadiene ring or the condensed ring that contains the cyclopentadiene ring can further replace the one or more substituting groups that are selected from C1-C20 alkyl, C6-C30 aryl, C2-C20 thiazolinyl and C6-C30 aryl C1-C20 alkyl;

R ¹～R ⁴Represent independently hydrogen atom, halogen atom, C1-C20 alkyl, C3-C20 cycloalkyl, C6-C30 aryl, C6-C30 aryl C1-C10 alkyl, C1-C20 alkoxyl group, C3-C20 alkyl siloxy, C6-C30 aryl siloxy-, C1-C20 alkylamino, C6-C30 arylamino, C1-C20 alkyl sulfenyl, C6-C30 artyl sulfo or nitro, perhaps R ¹～R ⁴In thereby each can link to each other with adjacent substituting group via the C3-C12 alkylidene group that contains or do not contain condensed ring or C3-C12 alkenylene and forms aliphatics ring or monocycle or encircle aromatic nucleus more;

Ar ¹Represent the C6-C30 aryl or contain the one or more heteroatomic C3-C30 heteroaryl that is selected from N, O and S;

X ¹And X ²Represent independently halogen atom, C1-C20 alkyl, C3-C20 cycloalkyl, C6-C30 aryl C1-C20 alkyl, C1-C20 alkoxyl group, C3-C20 alkyl siloxy, C6-C30 aryl siloxy-, C1-C20 alkylamino, C6-C30 arylamino, C1-C20 alkyl sulfenyl, C6-C30 artyl sulfo or

R ¹¹～R ¹⁵Represent independently hydrogen atom, halogen atom, C1-C20 alkyl, C3-C20 cycloalkyl, C6-C30 aryl, C6-C30 aryl C1-C10 alkyl, C1-C20 alkoxyl group, C3-C20 alkyl siloxy, C6-C30 aryl siloxy-, C1-C20 alkylamino, C6-C30 arylamino, C1-C20 alkyl sulfenyl, C6-C30 artyl sulfo or nitro, perhaps R ¹¹～R ¹⁵Form aliphatics ring or monocycle or encircle aromatic nucleus more thereby can link to each other with adjacent substituting group via the C3-C12 alkylidene group that contains or do not contain condensed ring or C3-C12 alkenylene; With

R ¹～R ⁴, R ¹¹～R ¹⁵, X ¹And X ²Described alkyl, aryl, cycloalkyl, aralkyl, alkoxyl group, alkyl siloxy, aryl siloxy-, alkylamino, arylamino, alkyl sulfenyl or artyl sulfo; R ¹～R ⁴Or R ¹¹～R ¹⁵In each ring that links to each other with adjacent substituting group and form via alkylidene group or alkenylene; Or Ar ¹Described aryl or heteroaryl can further replace the one or more substituting groups that are selected from halogen atom, C1-C20 alkyl, C3-C20 cycloalkyl, C6-C30 aryl, C6-C30 aryl C1-C10 alkyl, C1-C20 alkoxyl group, C3-C20 alkyl siloxy, C6-C30 aryl siloxy-, C1-C20 alkylamino, C6-C30 arylamino, C1-C20 alkyl sulfenyl, C6-C30 artyl sulfo, nitro and hydroxyl are arranged.

2. method for preparing ethylene copolymer, described method comprises:

(a) in one or more reactors, in the presence of the catalyst composition that contains the transition-metal catalyst that is represented by chemical formula (1), make ethene and one or more C3-C18 alpha-olefin comonomer carry out solution polymerization, thereby produce the first multipolymer;

(b) at least one other reactor, with step (a) in used identical catalyst composition in the presence of, in the temperature that is higher than step (a) temperature of reaction, make ethene or ethene and the reaction of one or more C3-C18 alpha-olefins, thereby prepare the second multipolymer by solution polymerization

Wherein the amount of step (a) and ethene (b) and one or more C3-C18 alpha-olefin comonomer is the ethene of 60 % by weight～99 % by weight and the alpha-olefin comonomer of 1 % by weight～40 % by weight;

(c) utilize inline mixer that described the first multipolymer is mixed with described the second multipolymer, and so that described ethylene copolymer comprises the polymkeric substance of step (b) preparation of the polymkeric substance of step (a) preparation of 10 % by weight～70 % by weight and 30 % by weight～90 % by weight

[Chemical formula 1]

In this formula, M represents the transition metal of the periodic table of elements the 4th family;

Cp represents η ⁵-being connected to the cyclopentadiene ring of described core metal M or containing the condensed ring of cyclopentadiene ring, wherein said cyclopentadiene ring or the condensed ring that contains the cyclopentadiene ring can further replace the one or more substituting groups that are selected from C1-C20 alkyl, C6-C30 aryl, C2-C20 thiazolinyl and C6-C30 aryl C1-C20 alkyl;

R ¹～R ⁴Represent independently hydrogen atom, halogen atom, C1-C20 alkyl, C3-C20 cycloalkyl, C6-C30 aryl, C6-C30 aryl C1-C10 alkyl, C1-C20 alkoxyl group, C3-C20 alkyl siloxy, C6-C30 aryl siloxy-, C1-C20 alkylamino, C6-C30 arylamino, C1-C20 alkyl sulfenyl, C6-C30 artyl sulfo or nitro, perhaps R ¹～R ⁴In thereby each can link to each other with adjacent substituting group via the C3-C12 alkylidene group that contains or do not contain condensed ring or C3-C12 alkenylene and forms aliphatics ring or monocycle or encircle aromatic nucleus more;

Ar ¹Represent the C6-C30 aryl or contain the one or more heteroatomic C3-C30 heteroaryl that is selected from N, O and S;

X ¹And X ²Represent independently halogen atom, C1-C20 alkyl, C3-C20 cycloalkyl, C6-C30 aryl C1-C20 alkyl, C1-C20 alkoxyl group, C3-C20 alkyl siloxy, C6-C30 aryl siloxy-, C1-C20 alkylamino, C6-C30 arylamino, C1-C20 alkyl sulfenyl, C6-C30 artyl sulfo or

R ¹¹～R ¹⁵Represent independently hydrogen atom, halogen atom, C1-C20 alkyl, C3-C20 cycloalkyl, C6-C30 aryl, C6-C30 aryl C1-C10 alkyl, C1-C20 alkoxyl group, C3-C20 alkyl siloxy, C6-C30 aryl siloxy-, C1-C20 alkylamino, C6-C30 arylamino, C1-C20 alkyl sulfenyl, C6-C30 artyl sulfo or nitro, perhaps R ¹¹～R ¹⁵Form aliphatics ring or monocycle or encircle aromatic nucleus more thereby can link to each other with adjacent substituting group via the C3-C12 alkylidene group that contains or do not contain condensed ring or C3-C12 alkenylene; With

R ¹～R ⁴, R ¹¹～R ¹⁵, X ¹And X ²Described alkyl, aryl, cycloalkyl, aralkyl, alkoxyl group, alkyl siloxy, aryl siloxy-, alkylamino, arylamino, alkyl sulfenyl or artyl sulfo; R ¹～R ⁴Or R ¹¹～R ¹⁵In each ring that links to each other with adjacent substituting group and form via alkylidene group or alkenylene; Or Ar ¹Described aryl or heteroaryl can further replace the one or more substituting groups that are selected from halogen atom, C1-C20 alkyl, C3-C20 cycloalkyl, C6-C30 aryl, C6-C30 aryl C1-C10 alkyl, C1-C20 alkoxyl group, C3-C20 alkyl siloxy, C6-C30 aryl siloxy-, C1-C20 alkylamino, C6-C30 arylamino, C1-C20 alkyl sulfenyl, C6-C30 artyl sulfo, nitro and hydroxyl are arranged.

3. the method for preparing ethylene copolymer as claimed in claim 1 or 2, wherein M is Ti in the described transition-metal catalyst of chemical formula (1) expression.

4. the method for preparing ethylene copolymer as claimed in claim 3, wherein said transition-metal catalyst are selected from the compound by the expression of one of following chemical formula:

[Chemical formula 1-1]

[Chemical formula 1-2]

[Chemical formula 1-3]

[Chemical formula 1-4]

[Chemical formula 1-5]

[Chemical formula 1-6]

[Chemical formula 1-7]

[Chemical formula 1-8]

[Chemical formula 1-9]

[Chemical formula 1-10]

[Chemical formula 1-11]

[Chemical formula 1-12]

[Chemical formula 1-13]

[Chemical formula 1-14]

In the described formula, R ²¹～R ²⁶Represent independently hydrogen atom, halogen atom, C1-C20 alkyl, C3-C20 cycloalkyl, C6-C30 aryl, C6-C30 aryl C1-C10 alkyl, C1-C20 alkoxyl group, C3-C20 alkyl siloxy, C6-C30 aryl siloxy-, C1-C20 alkylamino, C6-C30 arylamino, C1-C20 alkyl sulfenyl, C6-C30 artyl sulfo or nitro, or R ²¹～R ²⁶Thereby in each can be connected with adjacent substituting group via the C3-C12 alkylidene group that contains or do not contain condensed ring or C3-C12 alkenylene and form aliphatics ring or monocycle or encircle aromatic nucleus more; R ²¹～R ²⁶Described alkyl, aryl, cycloalkyl, aralkyl, alkoxyl group, alkyl siloxy, the aryl siloxy-, alkylamino, arylamino, alkyl sulfenyl or artyl sulfo can further replace and be selected from halogen atom, the C1-C20 alkyl, the C3-C20 cycloalkyl, the C6-C30 aryl, C6-C30 aryl C1-C10 alkyl, the C1-C20 alkoxyl group, the C3-C20 alkyl siloxy, C6-C30 aryl siloxy-, the C1-C20 alkylamino, the C6-C30 arylamino, C1-C20 alkyl sulfenyl, the C6-C30 artyl sulfo, one or more substituting groups of nitro and hydroxyl;

Cp represents η ⁵-being connected to the cyclopentadiene ring of described core metal M or containing the condensed ring of cyclopentadiene ring, wherein said cyclopentadiene ring or the condensed ring that contains the cyclopentadiene ring can further replace the one or more substituting groups that are selected from C1-C20 alkyl, C6-C30 aryl, C2-C20 thiazolinyl and C6-C30 aryl C1-C20 alkyl; With

X ¹And X ²Expression methyl or Cl.

5. the method for preparing ethylene copolymer as claimed in claim 4, wherein said transition-metal catalyst is selected from following compound:

In the described formula, Cp represents η ⁵-being connected to the cyclopentadiene ring of described core metal M or containing the condensed ring of cyclopentadiene ring, the wherein said condensed ring that contains the cyclopentadiene ring can further replace the one or more substituting groups that are selected from C1-C20 alkyl, C6-C30 aryl, C2-C20 thiazolinyl and C6-C30 aryl C1-C20 alkyl; With

X ¹And X ²Expression methyl or Cl.

6. the method for preparing ethylene copolymer as claimed in claim 1 or 2, wherein said catalyst composition comprises described transition-metal catalyst; With the promotor that is selected from aluminium alkoxide compound, alkylaluminium cpd and boron compound and composition thereof.

7. the method for preparing ethylene copolymer as claimed in claim 6, the ratio of wherein said transition-metal catalyst and described promotor are take transition metal M: the molar ratio computing of aluminium atom is as 1:1～1:2, and 000.

8. the method for preparing ethylene copolymer as claimed in claim 6, the ratio of wherein said transition-metal catalyst and described promotor are take transition metal M: the molar ratio computing of boron atom is as 1:0.1～1:50.

9. the method for preparing ethylene copolymer as claimed in claim 7, the ratio of wherein said transition-metal catalyst and described promotor are take transition metal M: the boron atom: the molar ratio computing of aluminium atom is as 1:0.1～50:1～1,000.

10. the method for preparing ethylene copolymer as claimed in claim 1 or 2, wherein the temperature of reaction of step (a) is 80 ℃～210 ℃, the temperature of reaction of step (b) is 90 ℃～220 ℃, and the reaction pressure of each step is 20atm～500atm.

11. the method for preparing ethylene copolymer as claimed in claim 1 or 2, wherein step (a) and described alpha-olefin comonomer (b) are selected from propylene, 1-butylene, 1-amylene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecylene and composition thereof.

12. the ethylene copolymer of method preparation according to claim 1 and 2.

13. ethylene copolymer as claimed in claim 12, the polymkeric substance of wherein said step (a) preparation have melt index and the 0.860g/cm of 0.001g/10 minute～2.0g/10 minute ³～0.925g/cm ³Density, and the polymkeric substance of described step (b) preparation has melt index and the 0.900g/cm of 0.1g/10 minute～100.0g/10 minute ³～0.970g/cm ³Density.

14. ethylene copolymer as claimed in claim 12, described ethylene copolymer are density is 0.910g/cm ³～0.940g/cm ³Linear low density polyethylene copolymers.

15. ethylene copolymer as claimed in claim 12, described ethylene copolymer are density is 0.900g/cm ³～0.910g/cm ³Extra-low density ethylene copolymer.

16. ethylene copolymer as claimed in claim 12, described ethylene copolymer has 2.8～30 molecular weight distributing index.

17. ethylene copolymer as claimed in claim 12, described ethylene copolymer is used for blown film, casting film, injection moulded products, blowing product or pipe.

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